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The Big Book of Why · Plant Kingdom
Five illustrated books that answer the questions your child actually asks, so you don’t have to guess. A picture on every page, no screen required.
For curious kids aged 6 to 12
Buy 2 books, get the 3rd free
- Answers you can read aloud in under a minute, and trust to be correct
- Every spread starts with a question kids really ask, so they keep turning pages
- Read together from about 5, alone from 7 or 8; one shelf works for siblings
Launch offer
Your bookPlant Kingdom
Book 1Plant Kingdom
Extreme Survival and Exploration
Amazing Universe
Fun With Science
Our Earth Home
Plant Kingdom
Add a Field Lab setSave 25% on each set when you take all 5 books
In stock, ships in 1 to 2 business days
Free shipping on 2 books or more · 30-day money-back guarantee
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- 30-day guaranteeFull refund, no questions
- Ships in 1–2 daysTracked to your door
- 4.6 out of 51,200+ reviews
- Secure checkout
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How to read it
Open any page. Each spread starts with a question a child actually asks, then answers it in plain language, with a picture to look at while you read.
There is no order to follow and nothing to finish. Two minutes before bed works, and so does an hour on the floor with the next four questions after it.
What is inside
Five softcover volumes: Our Earth Home, Fun With Science, Extreme Survival and Exploration, Plant Kingdom and Amazing Universe. Full colour throughout, with a picture on every page.
Questions like why polar bears stay warm, why colours fade underwater and how deserts get cold at night, each one answered on its own spread.
Shipping & returns
Shipping is a flat $6.95 worldwide, and free on orders of 2 books or more. Orders leave us within 1 to 2 business days with tracking. United States 7 to 15 business days, Australia and New Zealand 9 to 19, Singapore 5 to 12.
If the books are not right, email us within 30 days for a full refund. No restocking fee.
What your child gets, and what you get back
Every spread opens with a question a child asks out loud. Why do polar bears stay warm. Why does thunder mean lightning is close.
Full colour throughout. A child who cannot yet read the answer can still sit with the page and work out most of it from the picture.
Each question is answered accurately and in plain language, the way a scientist would explain it to a child rather than the way a textbook would.
Our Earth Home, Fun With Science, Extreme Survival and Exploration, Plant Kingdom and Amazing Universe. Buy one, or take the whole set.
Built for the questions you can’t answer in the car
The ones children actually ask
Why do polar bears stay warm. Why do colours fade underwater. How do cacti store water. Every spread in the series opens with a question of that kind, printed at the top of the page.
That is the part most science books skip, and it is the part a child arrives with.
Plain language, still accurate
The answer underneath is short, written in words a child of six can follow, and it is correct. Nothing is simplified into something untrue.
If you read it aloud you will not find yourself editing as you go.
On every page, in full colour
Each answer sits next to an illustration of the thing it describes, so the page still works for a child who is looking rather than reading.
All five volumes are built the same way, from Our Earth Home through to Amazing Universe.
Two minutes at bedtime, or an hour on the floor
How families actually use these books.
Open any page
There is no first chapter and nothing to keep up with. Let your child open the book wherever it falls and start there.
Read the question
Every spread begins with one. Read it out loud, look at the picture together, and let your child guess before anyone reads on.
Read the answer
Then read what is underneath. Two minutes before bed is enough, and so is an hour on the floor with four more questions after it.
Why every page starts with a question
Children do not ask for a chapter on thermodynamics. They ask why thunder means lightning is close, and they ask it in the car, at dinner, or ten minutes after bedtime.
The Big Book of Why is written from that side. Each spread takes one real question, puts a picture next to it, and answers it in plain language without getting it wrong.
- Five volumes, softcover, full colour throughout.
- A question at the top of every spread, an answer underneath.
- Written for ages 6 to 12, read together from about five.
The plain facts about the set
Our Earth Home, Fun With Science, Extreme Survival and Exploration, Plant Kingdom, Amazing Universe
Read together from about five, read alone from seven or eight
Email us within 30 days for a full refund, with no restocking fee
How it compares to what’s already in the house
 The Big Book of Why |
A children's encyclopedia | Screen-time science videos | |
|---|---|---|---|
| Every spread starts from a question | |||
| A picture on every page | |||
| Books in the set | 5 | Varies | None |
| Price | $29.99 | Varies | Subscription |
| Answers written in plain language for a child | |||
| Works with no screen and no signal | |||
| Nothing to subscribe to | |||
| 30-day money-back guarantee from Whys Books |
Rated 4.6 out of 5 by the parents who read them.
From over 1,200 reviews across our stores. Here are some recent ones, exactly as written.
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“Beautiful books and excellent quality. My daughter loved the colourful illustrations and wanted to read them immediately.”
Verified buyer -
“The book is engaging and well made. Delivery took a little longer than expected, but it arrived safely and my son really enjoys it.”
Verified buyer -
“WhyBooks makes learning feel fun instead of like homework. The stories are easy to understand and perfect for bedtime reading.”
Verified buyer -
“Really lovely educational content. Some parts were slightly advanced for my four-year-old, but we enjoyed reading and discussing them together.”
Verified buyer -
“My son normally loses interest in books quickly, but he keeps asking us to read this one again. Definitely worth buying.”
Verified buyer -
“Good quality printing with bright, clear illustrations. I would love to see more titles available as a discounted bundle.”
Verified buyer -
“I purchased several books for my classroom and the children responded really well. They created some great conversations and learning moments.”
Verified buyer -
“A great alternative to giving children more screen time. The book was a little smaller than I expected, but the content was excellent.”
Verified buyer -
“This was my first order from WhyBooks and I’m very impressed. Good value, helpful delivery updates and books that children genuinely enjoy.”
Verified buyer -
“The book arrived well packaged and looked like the photos online. My daughter enjoyed it, and I’ll probably purchase another title soon.”
Verified buyer
30 days to see how it lands
Read them with your child. If the books are not right, email us within 30 days and we will refund you in full. No restocking fee and nothing to send back at your own cost.
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Answers to the questions parents ask
What age are these books for?
They are written for ages 6 to 12. From about five they work as a read-together book, and most children start reading them on their own somewhere around seven or eight. The pictures carry a lot of the page, so a younger child can still sit with one.
How is this different from a children's encyclopedia?
An encyclopedia is organised around topics. These books are organised around questions. Every spread starts with something a child actually asks, such as why colours fade underwater, and answers that one thing in plain language with a picture beside it. You read a question, not a chapter.
How long does shipping take?
Orders leave us within 1 to 2 business days with tracking. United States 7 to 15 business days, Australia and New Zealand 9 to 19, Singapore 5 to 12. Shipping is a flat $6.95 worldwide, and free on orders of 2 books or more.
What if my child does not take to them?
Email us within 30 days and we will refund you in full. There is no restocking fee and no form to fill in. Books that have been opened and read are fine.
Can I add a gift note?
Yes. There is a ready-to-gift bag for $3.99 in the cart, and you can add a note with it at checkout. A single volume or the full set both fit.
Do I need all five?
No. Each volume stands on its own at $29.99, so plenty of people start with the one that matches what their child is already asking about. The offers are there if you want more than one: buy 2 get 1 free, or all five for $89.97, which is 40% off.
What are the Field Lab sets?
Two 8-book STEM sets, This Is Chemistry and This Is Physics, for the same 6 to 12 age range. When you take all five Big Book of Why books you can add either set at 25% off, and the discount is applied automatically in the cart.