Rethinking Subtraction as Addition: Using the Additive Inverse

This lesson teaches how to rethink subtraction problems as addition problems using the additive inverse. It begins with a review of integers and explains common mistakes in subtracting integers. The lesson then demonstrates how to use the additive inverse on a number line to solve subtraction problems, providing examples to illustrate the concept. Finally, it addresses more complex subtraction problems, showing how to convert them into addition problems using the additive inverse.

What is a common mistake when subtracting integers?

• Subtracting numbers as if they are both positive and then applying the sign.

• Adding numbers without considering their signs.

• Dividing numbers instead of subtracting.

• Multiplying numbers instead of subtracting.

What is the additive inverse of a number?

• The number itself.

• The number multiplied by two.

• The opposite of the number.

• The number divided by two.

How do you solve 8 - 3 using the additive inverse?

• Add 8 and 3.

• Subtract 3 from 8.

• Add 8 and -3.

• Subtract -3 from 8.

What is the result of 7 - 13 using the additive inverse?

• 20

• -6

• 6

• -20

How can you express 15 - 6 as an addition problem?

• 15 - 6

• 15 - (-6)

• 15 + (-6)

• 15 + 6

What is the result of -2 - (-9) using the additive inverse?

• -11

• 11

• 7

• -7

How do you handle multiple negative signs in subtraction?

• Ignore them.

• Add the numbers directly.

• Multiply the numbers.

• Use the additive inverse to simplify.