“Guess How Many” – See your Guesstimators Become Estimators with this Delightful Picture Book

Guess How Many
“Guess How Many” Book

“Guess How Many” – A book about estimation

“Guess How Many” introduces children to the idea of estimation and what it means to estimate accurately. This captivating story introduces us to Daisy Duncan who dreams of being a teacher. She attempts to teach her brother Derek how to estimate and in the process teaches the reader too, without them even realising it.

It is an excellent way to introduce a topic on estimation and gives children a good understanding of what it entails before they begin to explore it practically for themselves. It can be revisited on a number of occasions as the children begin to understand the concepts and consolidate their learning. It would look great on your estimation station and children will be eager to visit it and explore the table you have set up.

Although this is essentially a book about estimation there are lots of other mathematical concepts permeating throughout the book which I will outline below.

Number Sense

In order to estimate children need to develop a good understanding of what quantities of numbers look like as their early estimates can be way out. An understanding of this is also useful when developing a number of other mathematical concepts. Through the illustrations, children are able to see 100, 20, 15 etc.

Estimation Jars from “Guess How Many”

Children begin to recognise that 100 is actually a lot of items and 12 looks like a lot less.


Children will inadvertently develop an awareness of capacity as the jar stays the same size throughout the book while the number of objects that fit into the jar decreases. This can be linked to the size of the objects which increases as the quantity decreases. Children can be made aware of this concept and explore it practically for themselves.

Number Recognition

I have purposefully chosen the numbers beyond 10 in the book that children often have difficulty recognising and remembering – 20, 15, 12. When learning numbers beyond 10 children will often say “fiveteen”. Visiting it in the book will help the children to remember and recognise it as fifteen. Again, 12 can be difficult to remember as it is one of the few numbers beyond ten that isn’t a teen number, it doesn’t follow a particular pattern. The book again aims to reinforce the recognition of this number.


When children first learn how to count objects they are supported by being able to move them as they count or line them up to making counting easier. This book gives children the opportunity to count objects that can’t be moved and are not necessarily lined up in a regular arrangement.

1 More Than

At the end of the book Derek makes his final estimation. Daisy is delighted that Derek has finally had a good guess. Derek is confused as his guess doesn’t match the quantity. Daisy explains that estimations don’t have to be accurate but close to the number of items.

Derek’s guess is only one more than the actual number. This can provide the opportunity to suggest other numbers that would be good estimations for different quantities. For example, if I had 5 objects in my jar, what would be a good estimate. Children can be encouraged to explore the idea of 1 more and 2 more. Once they are confident with this, they could then explore the idea of 1 less and 2 less in the same way.

For more information on developing number sense then visit my blog on the number system.

Using the book, children can explore a whole range of mathematical concepts without even realising that they are learning. Read regularly, the children will become familiar with the language and ideas in a fun and enjoyable way. Add it to your estimation station for the children to revisit independently and explore some of the concepts and ideas introduced. If you would like a copy of “Guess How Many” then click on the picture below.

Daisy Duncan from “Guess How Many”

If you would like to find out more about estimating then visit my estimating blog. If you would like a copy of my estimating pack which supports the concepts in the book then visit my teacherspayteachers store or my tes store.