Children should learn to practice adding by tens and hundreds quickly.

Learning to add by 100 is a good way to practice mental math and can help kids get better at math in general.

Also, learning to add by 100 can help kids understand place value because they have to think about the tens place and the ones place when they add and carry digits. This skill can also help kids break big numbers into smaller, easier-to-handle pieces when working with them.

Overall, learning to add by 100 is a helpful math skill for kids to have because it helps them solve problems more quickly and correctly.