The subtraction facts (under 10 and 11-18) are typically the most difficult for students to learn and recall quickly. Hopefully, using several strategies will support their learning.

1. One of the best ways to help students recall their subtraction facts is for them to know their addition facts. Subtraction is the opposite of addition. Taking the addition facts and turning them around will support learning the subtraction facts. (This is true for multiplication and division, as well.)

2. Fact Families: If students know their addition facts, they should quickly learn that certain facts are related like the members of a family. The numbers 7, 8, 15 have a special relationship to each other.

7 + 8 = 15 8 + 7 =15 15 - 7 = 8 15 - 8 =7

This strategy works for all facts.

3. Counting Back: This strategy can be used when students are subtracting small numbers like, 1, 2, 3 from larger numbers. If students have the fact 12 - 3 = ?, they can count back or use touch math by saying "12", and counting back "11, 10, 9." 12 - 3 = 9 because the students counted back 3 numbers.

4. Counting Up: This strategy works when the numbers that are subtracted are close to each other. Example: 12 - 9 = ? The students can think about what number added to 9 will equal 12 or count up saying "9, 10, 11, 12." (Not on their fingers.)

I want to add an important note about when we use the operation of subtraction. Students often come to second grade and think that every subtraction problem is a "take away" problem, and that is just not true. When we add, we are always joining groups. There are three different reasons, however, that we can and do use subtraction.

1) Take away: There are 9 birds at our feeders. Three birds fly away. How many birds are left? 9-3=6 birds.

2) Compare: There are 14 boys and 12 girls in Mrs. Brown's class. How many more boys (or less girls) are there is our class? 14-12=2 more boys. As you can see, nothing was taken away. The numbers were compared.

3) Find the missing addend: Suzie brought 26 cupcakes to class. Eleven are vanilla. How many are chocolate (missing addend)? 11+ ? = 26 so 26-11=15 chocolate cupcakes. Again, nothing was taken away.

Students get very confused if they are only thinking that subtraction is a "take away" problem. They read the comparing and find the missing addend problems and cannot figure out what operation to use. It is important for students to understand the three ways we use subtraction, that the symbol for subtraction is a minus sign, and that we do not "take away" with every subtracton problem.

The last word of encouragement about learning addition and subtraction facts is to practice, practice, practice.