Here are two number sentences that
have a missing number. What times 10 equals 20. 20 divided by 10 equals what. What is the missing number that
completes both of the number sentences? Is it 30, three, 10, or two?
We’re being asked to find these two
missing numbers. And we’re told that the missing
numbers are the same number. So which number would fit in both
of these number sentences? In this sentence, we have to find
the number that we multiply by 10 to give us a product of 20. What times 10 is 20? We know that one lot of 10 is 10
and two lots of 10 makes 20. One times 10 is 10; two times 10 is
20. We found our first missing
number. We modeled the number 20 using
blocks of 10. And we used our knowledge of the 10
times table to say that two times 10 equals 20. If two times 10 is 20, then 20
divided by 10 equals two. This is the missing number that
completes both number sentences. Two times 10 equals 20. 20 divided by 10 equals two.