Adding Doubles

Teaching Notes

Students add a number to itself.

Before You Begin

• Counting and adding two numbers

Teaching Steps for Parents and Teachers

1. Set out two groups of 6 objects. Check that the groups are equal.
2. Read 6 + 6 aloud, then combine and count the groups.
3. Check that the sum is 12 and write it in the answer box.
4. Split 12 objects into groups of 6 again. Check that they match the original groups.

Worked Examples

6 + 6 = 12

1. Combining 6 objects and 6 objects gives 12 objects.

Answer: 12

Common Mistakes and How to Help

Writing only one addend as the answer

Use objects to show that 6 is the number in one group. The answer counts both groups together.

Correcting the answer without explaining why

Keep the two groups separate so the student includes both groups and counts each object once. Have the student start again at the first incorrect step.

Questions to Check Understanding

• Can you show 6 + 6 with two groups?
• What does each number in the worked example represent in the original problem?
• Can you use the same method when the numbers change?

Practice Advice

Work through the example together and have the student explain why the answer is 12. Ask the student to explain the first two problems aloud, then solve the next three independently. Review the intermediate steps as well as the final answers. If an error repeats, return to the difficult teaching step before assigning more problems.

Next Practice

• Choose New Numbers for more practice with the same conditions. Ask the student to explain the reasoning as well as give the answer.
• If the student cannot explain the method independently, use smaller numbers to explore the same relationship first.