整十数

理解整十数（10、20、30……90）表示1到9个十和0个一。

Understand that the multiples of 10 (10, 20, 30 … 90) represent one to nine tens and 0 ones

学习证据 / Evidence

• 解释30表示3个十和0个一
• 用5根十位棒和0个单位小方块表示50
• 把整十数与它们的十位表示对应起来

• Explain that 30 means 3 tens and 0 ones
• Represent 50 using 5 tens rods and no unit cubes
• Match decade numbers to their tens representation

评估问题 / Assessment

{{name}}能解释60表示6个十和0个一，并说明这就是个位上用0占位的原因吗？

Can {{name}} explain that 60 means 6 tens and no ones — and that this is why the ones column has a zero as a placeholder?