Mathematically proficient students look over their work to ensure that it is labeled correctly and that their solutions are accurate and make sense.

Check My Work is a strategy that helps students recognize if and where they’ve made a mistake in the way they approached the problem or made a calculation error. This strategy helps students learn to pay attention to details.

If you see students who . . .

• solve a problem with confidence, yet arrive at an incorrect answer
• work quickly when solving problems

This strategy benefits all mathematicians and should be introduced to and used by everyone.

To regularly solve problems accurately, students need to be able to independently check that their work is labeled correctly as well as correct any miscalculations they made while solving.

For students to be successful with this strategy they must be able to

• calculate accurately and efficiently,
• be flexible in their thinking,
• explain their work, and
• reason abstractly and concretely.

Modeling a think-aloud during the “I Do” focus lesson: 
Explain to students that they are going to learn how to check their work and distinguish correct logic from incorrect logic. This helps us make sure we have labeled our work and solved the problem correctly. We do this because we want to make sure that our work makes sense and that we’ve arrived at the correct solution.

Using the strategy Check My Work looks like this:
Once you have solved a problem and found a solution, you go back through your work to make sure it is free from mistakes and that you have labeled your work and the solution accurately.

You will know you are using this strategy when you can easily explain how you arrived at a solution, your work makes sense, and your work is regularly free from mistakes.

Suggested Language

• Did I express the problem accurately? (Do my numbers and symbols in the equation make sense?)
• Did I answer what the problem is asking me to solve?
• Could I explain how I solved this problem to a friend?
• Did I label all of my work? Are my labels consistent?
• Would someone be able to follow my method for solving if I was not there to explain?

• Teach students to mark up the problem.
• Teach students to look at how the problem is organized to determine if they’ve already seen and solved a similar problem.
• Introduce students to multiple ways to solve the same type of problem. (Mental math is excellent for showcasing this.)

These strategies may provide support before, during, and after teaching this strategy:

• Guide to Using Math Tools
• Check Solution Using a Different Method