It is probably because humans have ten fingers that we have our familiar base-10 number system: ten ones make a ten; ten tens make a hundred; ten hundreds make a thousand. Because our number system is based on tens, making tens is a critical mental math skill. Here, we use ten-frames to visualize the process.
Step by step | Making tens
- Count up to the next ten. Remember this count.
- Add tens to the count until the goal is met.
Example | Making tens
Q: 7 + ____ = 20
A: Counting up from 7, we count 3 more to reach 10. One more ten
gives 20, for a total count of 13:
7 + 13 = 20.