When adding, students are reminded that when they add to one number to make a multiple of 10, then they must subtract the same amount from the other addend.

For example, for the problem 398 + 142 students responded by explaining the strategy they thought was best suited to solve the problem:

- Making a hundred is the easiest and quickest, especially since you only needed to add on 2.
*(Meaning: add the 2 ones from 142 to the 398 to make 400 + 140)* - I prefer the arrow way because once you add 2 to make 400, it’s easy to add a hundred and 4 tens.

The various strategies students learn in this module are designed to develop students’ conceptual understanding of addition and subtraction using models, drawings, properties of operations, and strategies based on place value. At the same time, students relate these strategies to written methods such as arrow notation and number bonds.

This year, the students have developed a much deeper understanding of number operations in base ten and have gained number sense.

While we have always used manipulatives and drawings to teach math. Arrow notation and number bonds are new strategies to our teaching. These methods have provided students with multiple strategies to solve mathematical problems. This is a solid foundation on which they will build their mathematical knowledge in the coming years.