《MathStart》系列為美國HarperCollins出版的暢銷數學啟蒙書。作者Stuart J. Murphy認為數學與日常生活息息相關，他為了建立小朋友基礎的數學概念與知識，讓小朋友輕鬆愉快地學習數學，因而精心設計了這套生活化的《MathStart》數學啟蒙繪本，從生活話題與情境故事，讓小朋友有效地吸收數學概念。
全系列分為三個Level，Level 3 包含進階的數字計算(如乘、除法)學習，與思考邏輯的強化。
It is so much fun to be a penguin—especially when you can swirl around on your very own ice scooter. Perry really wants one, but they cost 9 clams and he doesn't have a clam to his name. Then mom pays him 4 clams to trim the ice in front of their house. Perry decides to make a chart to track his savings. So far, so good! But then he goes to the Ice Circus with Fuzzy and it costs 5 clams. Fuzzy lends him the extra clam and now Perry is in debt and has to mark his chart at "-1." When Baldy loans him 2 clams for a Fishy Float, the total dips even further, to "-3." Will Perry be able to climb out of negative number territory, pay back his friends, and make enough money for a scooter? Good thing there's always plenty of snow to shovel!
The introduction of negative numbers extends a child's knowledge of the number system and is an important concept in algebra.
Books in the same series:
Paperback / For Ages: 6-8 / 40 pages