Lesson objective: Find 10 more and 10 less than a number by using a hundred chart

This lesson helps to build procedural skill with using a hundred chart to add or subtract 10. A hundred chart is used here because it supports students in adding or taking away one group of ten without needing to count by ones. The hundred chart shows how the tens place will increase or decrease by one ten. This work develops students' understanding that they can find ten more or ten less without needing to count.

Students engage in Mathematical Practice 7 (look for and make use of structure) as they add and subtract 10 by only changing the tens place by one ten.

**Key vocabulary:**

- add
- hundred chart
- place value
- subtract
- ten less
- ten more

**Special materials needed:**

- hundred chart
- number cube