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Psychology
Dec 12, 2025
86
4 pages
Lifespan development explores how humans grow and change from conception through old age. This guide breaks down key... Show more
Ever wonder how you grew from a tiny collection of cells into the person you are today? Development involves complex interactions between our genetics and environment. The nature-nurture debate examines whether our development comes from our genes or our experiences—most psychologists now recognize both are crucial.
Prenatal development happens in three key phases. First comes the germinal period (conception to 2 weeks) where rapid cell division transforms a zygote into an embryo. During the embryonic period , major organs develop starting with the head. The fetal period involves growth and refinement, with viability (ability to survive outside the womb) occurring around the 7th month.
Our genetic makeup forms our biological foundation. Genes are units of DNA that determine our traits, with dominant genes expressing themselves regardless of pairing, while recessive genes only show up when paired with another recessive gene. We have 23 pairs of chromosomes that carry these genetic instructions.
Quick Fact During infancy, babies are born with reflexes and demonstrate habituation—the ability to decrease their response to a repeated stimulus, showing early signs of learning and memory!
Piaget's theory explains cognitive development through structures and schemes (organized patterns of behavior). Children adapt to new information through assimilation (fitting new info into existing knowledge) and accommodation (changing their understanding based on new information).
Piaget's four-stage theory maps out how your thinking abilities develop from birth through adolescence. You start in the sensorimotor stage using senses and motor abilities to understand the world, developing object permanence. During the preoperational stage , you gain symbolic thinking and language. The concrete operational stage brings logical thinking and understanding of conservation and reversibility. Finally, the formal operational stage allows for abstract thinking.
Not all theories rely on distinct stages. The information-processing approach suggests development happens gradually through improvements in attention, memory, and thought processes—more like a smooth progression than distinct jumps between stages.
Vygotsky took a different approach, focusing on how we learn through social interactions. His key concept, the zone of proximal development, describes the gap between what you can do alone and what you can accomplish with help. This zone is where learning happens, supported by "scaffolding" from teachers or peers.
Learning Tip When tackling a difficult concept, think about your zone of proximal development. What parts can you understand independently, and where might you need a teacher or friend to help you grasp the idea?
Social and emotional development centers around attachment behavior—actions babies take to maintain closeness with caregivers. By 7 months, attachment becomes intense, and around 8-9 months, babies develop stranger anxiety. Psychologists assess attachment styles using the Strange Situation Technique to determine if a child has secure or insecure attachment patterns.
Did you know moms and dads often parent differently, and that's actually beneficial for development? Mothers typically interact more verbally with predictable patterns, focusing on education and calming children. Fathers tend to engage more physically with unpredictable play that creates emotional arousal. Both approaches contribute uniquely to a child's development.
Common misconceptions portray fathers as incompetent or less nurturing, but research shows they're equally capable caregivers. Fathers even use "motherese" when communicating with infants, showing their natural parenting abilities.
During adolescence, forming an identity becomes crucial. Marcia's theory identifies four identity statuses based on crisis (exploration) and commitment. You might experience identity diffusion (no exploration or commitment), identity foreclosure (commitment without exploration, often from parental pressure), identity moratorium (active exploration without commitment), or identity achievement (commitment after thorough exploration).
Real Talk Most teens cycle through different identity statuses before finding their path. If you're feeling uncertain about who you are or what you want, that's a normal part of the process!
Erikson's psychosocial theory explains development as a series of crises we must resolve to progress healthily. He believed development results from the interaction between our genetics and environment. Successfully navigating each crisis helps us move to the next developmental stage with psychological strength.
Erikson mapped out eight stages of psychosocial development spanning our entire lives. Each stage presents a specific crisis to resolve. In infancy, we face trust vs. mistrust. Early childhood brings autonomy vs. shame, followed by initiative vs. guilt in preschool years. School-age children work through industry vs. inferiority, while adolescents tackle identity vs. identity confusion.
The challenges continue into adulthood. Young adults (18-35) navigate intimacy vs. isolation, learning to form close relationships. Middle-aged adults (35-65) confront generativity vs. stagnation, focusing on productivity and caring for others. Finally, older adults (65+) face integrity vs. despair, reflecting on their lives and finding meaning.
As we enter later adulthood, different theories explain successful aging. The activity theory suggests older adults age successfully when they remain active and maintain social interactions. In contrast, the disengagement theory proposes that successful aging occurs when older adults voluntarily withdraw from certain social roles, allowing for a natural transition into later life.
Think About This Which theory of aging seems healthier to you? Notice how elders in your family or community approach aging—do they stay highly engaged or gradually shift their social roles?
Understanding these developmental stages helps us recognize that challenges at every age are normal and necessary for growth. Each crisis successfully resolved builds strength for facing the next life phase.
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Unit 6 review
PsychologyThis section is about the brain and how it works
PsychologyExplore the intricate processes of mitosis and meiosis, including key stages like prophase, metaphase, anaphase, and telophase. Understand the significance of crossing over, chiasmata, and independent assortment in genetic variation. This detailed summary covers the differences and similarities between mitosis and meiosis, highlighting their roles in cell division and reproduction.
PsychologyExplore Bowlby's monotropic theory of attachment, focusing on the internal working model, social releasers, and the impact of early relationships on parenting. This mind map covers key concepts such as secure and insecure attachment, the law of continuity, and the critical period for forming attachments. Ideal for students studying attachment theory and its implications in child development.
PsychologyExplore the findings of various studies on attachment types, including Jin (2012), Simonella (2014), and Van IJzendoorn & Kroonenberg (1988). This summary highlights the proportions of secure, insecure avoidant, and resistant attachments across different cultures, emphasizing the impact of cultural practices on attachment styles. Ideal for students studying attachment theory and its cultural implications.
Psychologyunit 6 review
PsychologyApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Lifespan development explores how humans grow and change from conception through old age. This guide breaks down key theories and stages, examining both biological factors (nature) and environmental influences (nurture) that shape our development throughout life.
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wonder how you grew from a tiny collection of cells into the person you are today? Development involves complex interactions between our genetics and environment. The nature-nurture debate examines whether our development comes from our genes or our experiences—most psychologists now recognize both are crucial.
Prenatal development happens in three key phases. First comes the germinal period (conception to 2 weeks) where rapid cell division transforms a zygote into an embryo. During the embryonic period , major organs develop starting with the head. The fetal period involves growth and refinement, with viability (ability to survive outside the womb) occurring around the 7th month.
Our genetic makeup forms our biological foundation. Genes are units of DNA that determine our traits, with dominant genes expressing themselves regardless of pairing, while recessive genes only show up when paired with another recessive gene. We have 23 pairs of chromosomes that carry these genetic instructions.
Quick Fact: During infancy, babies are born with reflexes and demonstrate habituation—the ability to decrease their response to a repeated stimulus, showing early signs of learning and memory!
Piaget's theory explains cognitive development through structures and schemes (organized patterns of behavior). Children adapt to new information through assimilation (fitting new info into existing knowledge) and accommodation (changing their understanding based on new information).
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Piaget's four-stage theory maps out how your thinking abilities develop from birth through adolescence. You start in the sensorimotor stage using senses and motor abilities to understand the world, developing object permanence. During the preoperational stage , you gain symbolic thinking and language. The concrete operational stage brings logical thinking and understanding of conservation and reversibility. Finally, the formal operational stage allows for abstract thinking.
Not all theories rely on distinct stages. The information-processing approach suggests development happens gradually through improvements in attention, memory, and thought processes—more like a smooth progression than distinct jumps between stages.
Vygotsky took a different approach, focusing on how we learn through social interactions. His key concept, the zone of proximal development, describes the gap between what you can do alone and what you can accomplish with help. This zone is where learning happens, supported by "scaffolding" from teachers or peers.
Learning Tip: When tackling a difficult concept, think about your zone of proximal development. What parts can you understand independently, and where might you need a teacher or friend to help you grasp the idea?
Social and emotional development centers around attachment behavior—actions babies take to maintain closeness with caregivers. By 7 months, attachment becomes intense, and around 8-9 months, babies develop stranger anxiety. Psychologists assess attachment styles using the Strange Situation Technique to determine if a child has secure or insecure attachment patterns.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Did you know moms and dads often parent differently, and that's actually beneficial for development? Mothers typically interact more verbally with predictable patterns, focusing on education and calming children. Fathers tend to engage more physically with unpredictable play that creates emotional arousal. Both approaches contribute uniquely to a child's development.
Common misconceptions portray fathers as incompetent or less nurturing, but research shows they're equally capable caregivers. Fathers even use "motherese" when communicating with infants, showing their natural parenting abilities.
During adolescence, forming an identity becomes crucial. Marcia's theory identifies four identity statuses based on crisis (exploration) and commitment. You might experience identity diffusion (no exploration or commitment), identity foreclosure (commitment without exploration, often from parental pressure), identity moratorium (active exploration without commitment), or identity achievement (commitment after thorough exploration).
Real Talk: Most teens cycle through different identity statuses before finding their path. If you're feeling uncertain about who you are or what you want, that's a normal part of the process!
Erikson's psychosocial theory explains development as a series of crises we must resolve to progress healthily. He believed development results from the interaction between our genetics and environment. Successfully navigating each crisis helps us move to the next developmental stage with psychological strength.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Erikson mapped out eight stages of psychosocial development spanning our entire lives. Each stage presents a specific crisis to resolve. In infancy, we face trust vs. mistrust. Early childhood brings autonomy vs. shame, followed by initiative vs. guilt in preschool years. School-age children work through industry vs. inferiority, while adolescents tackle identity vs. identity confusion.
The challenges continue into adulthood. Young adults (18-35) navigate intimacy vs. isolation, learning to form close relationships. Middle-aged adults (35-65) confront generativity vs. stagnation, focusing on productivity and caring for others. Finally, older adults (65+) face integrity vs. despair, reflecting on their lives and finding meaning.
As we enter later adulthood, different theories explain successful aging. The activity theory suggests older adults age successfully when they remain active and maintain social interactions. In contrast, the disengagement theory proposes that successful aging occurs when older adults voluntarily withdraw from certain social roles, allowing for a natural transition into later life.
Think About This: Which theory of aging seems healthier to you? Notice how elders in your family or community approach aging—do they stay highly engaged or gradually shift their social roles?
Understanding these developmental stages helps us recognize that challenges at every age are normal and necessary for growth. Each crisis successfully resolved builds strength for facing the next life phase.
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Unit 6 review
PsychologyThis section is about the brain and how it works
PsychologyExplore the intricate processes of mitosis and meiosis, including key stages like prophase, metaphase, anaphase, and telophase. Understand the significance of crossing over, chiasmata, and independent assortment in genetic variation. This detailed summary covers the differences and similarities between mitosis and meiosis, highlighting their roles in cell division and reproduction.
PsychologyExplore Bowlby's monotropic theory of attachment, focusing on the internal working model, social releasers, and the impact of early relationships on parenting. This mind map covers key concepts such as secure and insecure attachment, the law of continuity, and the critical period for forming attachments. Ideal for students studying attachment theory and its implications in child development.
PsychologyExplore the findings of various studies on attachment types, including Jin (2012), Simonella (2014), and Van IJzendoorn & Kroonenberg (1988). This summary highlights the proportions of secure, insecure avoidant, and resistant attachments across different cultures, emphasizing the impact of cultural practices on attachment styles. Ideal for students studying attachment theory and its cultural implications.
Psychologyunit 6 review
PsychologyApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Algebra
Algebra 1
Overige