鱷魚Casey牙痛。她的朋友是一隻珩鳥，主動說要幫助她拔掉牙齒。但是飛進鱷魚嘴裡是個好主意嗎？

在河邊跟隨鱷魚可怕的一週，學習如何使用加法與減法，並認識有關尼羅河鱷魚的有趣小知識！

《快樂學數學》系列啟動孩子的算術能力大躍進！孩子將會愛上書中的可愛動物與有趣故事，並在當中學習序數、數數(counting)、跳數(skip counting)、加法、減法等數學概念。

本系列每冊書中皆附贈互動素材(官網也提供素材檔案，可自行下載列印裁切)，讓每本書都是孩子動手體驗的學習工具。每則故事中也能讀到有趣的科學小知識，在快樂動手學習中，激發孩子對世界的好奇心與對數學的概念的理解。

Casey the Crocodile is having toothaches. Her friend, a plover bird, offers to help her pull out her bad teeth.

But is it a good idea to fly into a crocodile's mouth?

Follow the crocodile's dreadful week by the river and learn how to add and subtract.

Read fun facts about Nile crocodiles!

Jump start your child's advancement in numeracy with the Happy Learning Math series. Your child will delight in the fun stories about animals and encounter Math concepts, such as ordinal numbers, counting, skip counting, addition, subtraction and more.

Materials for interactive play and links to printables are also included, turning each book into a hands-on experiential learning tool. Fun Science facts are also weaved into each story to spark your child's curiosity about the world.

This book comes with bonus fun and interactive elements to reinforce your child's learning of Math concepts!