Basic Subtraction Background Information for Teachers, Parents and Caregivers
This page provides information to support educators and families in teaching K-3 students about basic subtraction. It is designed to complement the Basic Subtraction topic page on BrainPOP Jr.
Classes revisit and build on subtraction year after year, so the extent of what your children already know will vary. Though this movie addresses basic subtraction, BrainPOP Jr. plans on launching movies about more advanced subtraction, including two-digit numbers and regrouping. It is important for your children to understand that there are many different ways to subtract, such as drawing pictures; using counters, number lines, or hundreds charts; counting back; and using related fact families. Encourage your children to explore using concrete objects and different strategies, and provide plenty of opportunities for your children to use mental math during the day.
Remind your children that when you subtract, you find the difference between numbers by taking one away from the other. The answer to a subtraction problem is called the difference. Your children can employ different strategies to solve subtraction sentences, such as drawing pictures, using counters, or using number lines. They can also count back. Explain that they should start with the larger number and then count back the smaller number. For example, to solve the number sentence 6 – 2, they start with 6 and count back 2: 5, 4. Therefore, 6 – 2 = 4.
Another helpful subtraction strategy is using fact families or related facts. Remind your children that a fact family is a set of facts that use the same numbers, as in 7 + 2 = 9, 2 + 7 = 9, 9 – 2 = 7, and 9 – 7 = 2. Help your children see how addition and subtraction are related. For example, if your child knows that 4 + 4 = 8, then he or she can quickly figure out that 8 – 4 = 4. Related facts can also help children solve algebra problems. For example, in the problem 10 – ____ = 4, your child might know that 6 + 4 = 10, so that means 10 – 4 = 6 and 10 – 6 = 4. This will help your children see how addition and subtraction are two related operations. Number triangles are useful in finding related facts. We recommend watching the Basic Addition movie together as a review.
When some children face a word or story problem, they become confused or frustrated. Remind them to read the problem a few times until they can picture it in their mind. It might be useful to have them underline the important numbers and information in the problem. Then, ask them to re-tell the story in their own words. They can also draw, act out, or use classroom materials like counters or buttons to help them demonstrate and visualize the events in the problem. Finally, encourage them to write a corresponding number sentence to solve the problem.
Encourage your children to use these strategies to add and think of other ways to make subtraction faster and easier. Practice using different strategies to solve number sentences together. This will allow your children to become more comfortable with subtraction and help them master more complicated subtraction problems.
