Knowing the numbers that go together to make the sum of 10, strengthens our number sense and builds Fact POWER. It also builds a foundation for working with larger numbers. If you know your Fast 10s, you can expand this understanding to other multiples of ten.
If you know 2+8=10, then you can also know...
12+8=20 or 32+8=40 or 62+8=70
Today's lesson explored ways to solve problems with 3 or more addends. We looked at how the complements of 10 can help up solve these problems. We also recognized that no matter what order we add the numbers, the answer will be the same.
Does your child know their Fast 10s? Make it into a fun game. You say a number, they say the complement of 10. You can do this just about anywhere. Do you still have fact triangles? Find the Fast 10s and use them to practice the complements of 10 as well as other fact families.