Choosing an Operation Background Information for Teachers, Parents and Caregivers
This page provides information to support educators and families in teaching K-3 students about choosing an operation. It is designed to complement the Choosing an Operation topic page on BrainPOP Jr.
Share a math problem, such as, “Moby has 8 shells. He loses 2. How many shells does he have left?” Discuss the problem with children. How would they solve it? Remind them that when they come across a math problem, they should follow four steps to help them solve. First, they need to understand the problem. Then, they make a plan to solve it. Next, they carry out their plan to solve, and finally, they check their work. You may want to explore the Solving Word Problems topic as review.
Review with children that an operation is a way to solve a math problem, like addition, subtraction, multiplication, and division. Review each operation together.
When you add, you join groups or numbers together. Solve a few addition number sentences together, using manipulatives as needed.
When you subtract, you take away or find the difference between numbers. Pose a few subtraction number sentences together and model using number lines or counters to solve.
When you multiply, you put equal groups together to find the total. Help children understand that multiplying is really just adding the same number multiple times. Solve multiplication number sentences together, using both multiplication and repeated addition. Students may want to use arrays to help them solve.
When you divide, you split a larger group into smaller groups. Run through different division number sentences and use counters to solve.
Help children understand that when solving a math word problem, it can be challenging to figure out which operation to use. Guide them to look for words or phrases in the problem that can give clues about which operation to use.
Words like “add,” “sum,” “join,” “in all,” “all together,” and “in total” are clues that can tell them to add.
Words like “subtract,” “take away,” “less than,” “how many more,” “how much more,” and “how many left” are clues that can tell them to subtract.
Words like “multiply,” “times,” “join,” “in all,” “all together,” and “in total” are clues that can tell them to multiply.
Key words like “divide,” “split,” “how many,” and “each” can give clues that they can divide.
It is critical to point out that the same words or phrases can be clues for different operations. For example, “all together” can be a clue to add or to multiply. So it is important for students to read carefully and think about the problem before solving. What exactly is the problem asking them to figure out? Explore different word problems together and guide children in choosing the operation and solving the problem.