Patterns on the Hundred Chart

As we played a game on the hundred chart called "Plus, Minus, Stay the Same" the children have discovered a pattern that can help them as mathematicians. As you travel down a column on the hundred chart, the digit in the ones place stays the same, but the digit in the tens place increases by one. We practiced this pattern counting by tens starting with different numbers. We can count 7, 17, 27, 37, 47, etc... Or going backwards 92, 82, 72, 62, etc...

Although it's wonderful to find patterns, it's important to understand WHY they work and how they can help us. We had an interesting conversation about the why. With a little bit of debate, the children realized that the pattern works because you aren't adding any ones, you're just adding a ten each time you go down a column. It can help us add numbers quickly. For example, I can solve 42 + 14. If I know 14=10 + 4, I can add 10 + 42. Using our pattern, I quickly know the answer is 52. The final sum is 56 because 52 + 4 (leftover from the 14) is 56.

Talk about it with your children at home! :o)