Here he was working with number bonds to consider the decomposition of 10 and then writing that as an equation. He gets a sense of the whole/part relationship pictorially and that moves to a sentence that communicates the relationship mathematically.

The more he works with 10 he develops a fluency that will help support his thinking. Now I am seeing him work through subtraction problems using his fluency with 10 to solve.

The problem was:

*Micah has 17 markers and gives 3 away.*

What you see missing is a strategy to work with the 10. If he had ‘made 10’, not only would the work be more organized, he would be practicing the strategy of ‘completing a 10’ that is useful later on.

Not having a way to organize his work led to a mistake in his answer. This student didn’t organize his model and had to count and re-count his tally marks both when coming to the whole and after taking the 3 away. This led to a mistake in his ultimate answer.

**. The**

*10 frames***not only allow for his work to remain organized but it will be a great strategy as he begins to solve more complex problems.**

*10 frames*He has also begun to “make 10” in his head in order to solve addition and subtraction problems such as (9+4 = 13) and (14 – 6 = 8). It is this kind of fluency with numbers that I wish I would have had the opportunity to practice using a variety of strategies.

The strategies used in The Story of Units have given both of my sons this very gift. Which makes me grateful...and a little bit jealous.

**Michelle Helmer is a Staff Development Specialist with Integrated Education Services (IES) of Erie 2-Chautauqua-Cattaraugus BOCES. She is also the devoted mom of two boys and a secret "math geek."**