熟练的加减法

熟练回忆和运用20以内的加减法，并推导和运用相关的100以内的加减法。

Recall and use addition and subtraction facts to 20 fluently, and derive and use related facts up to 100

学习证据 / Evidence

• 快速回忆出7 + 8 = 15和15 − 8 = 7
• 利用6 + 4 = 10推导出60 + 40 = 100
• 根据5 + 5 = 10的知识推导出35 + 5 = 40

• Rapidly recall 7 + 8 = 15 and 15 − 8 = 7
• Use 6 + 4 = 10 to derive 60 + 40 = 100
• Derive 35 + 5 = 40 from knowledge that 5 + 5 = 10

评估问题 / Assessment

{{name}}能否快速回忆出像“9 + 7 = 16”和“16 − 7 = 9”这样的算式，并利用它们来计算像“90 + 70”这样更大的和呢？

Can {{name}} quickly recall facts like '9 + 7 = 16' and '16 − 7 = 9', and use those to help work out bigger sums like '90 + 70'?