小朋友見到這本書，不會當它是沉悶的練習本，只會當它是好玩的遊戲書！色彩繽紛加上擦擦寫寫，可增加小朋友學習減數時的樂趣。
學習減數往往比學習加數困難，很多小朋友懂得倒數亦不等於他懂得減數。本書特色是以數量增加的例子，再帶出數量減少的相反概念；接著就帶出數量比較"more or less"，讓小朋友循序漸進地掌握。
另外，有些準備小一面試的小朋友，校內課程未涉及20以內的減數，家長可以此書作為教材，在家講解減數的概念。
同系列書籍：
Key Skills Wipe-clean Adding Age 5-6
同時購買兩書9折 ($108／2本）
Key Skills Wipe-clean Maths Pack Age 5-6 (Adding & Subtracting)
A friendly wipe-clean book filled with subtraction activities that allow children to practice taking away numbers under 20, including 0. Part of the Usborne Key Skills series that supports the maths lessons children learn at school. The wipe-clean pages offer endless practice, and answers and secret notes for grown-ups are at the back.
Titles in the same series:
Key Skills Wipe-clean Adding Age 5-6
Special offer: $108/2 books
Key Skills Wipe-clean Maths Pack Age 5-6 (Adding & Subtracting)
Paperback / For Ages: 4-6 / 24 pages