Pre-Algebra · Quick Reference

Integers Cheat Sheet

Pre-Algebra · Lesson 5/10

In one line: integers extend our number system to include negative numbers — essential for representing things like debt, temperature below zero, or elevation below sea level.

Key Ideas

1Positive and Negative Integers. Whole numbers can be positive (1,2,3...), negative (-1,-2,-3...), or zero — together, these make up the integers.

2Adding Integers. Same signs: add the numbers and keep the sign. Different signs: subtract the smaller absolute value from the larger, and keep the sign of the larger.

3Subtracting Integers. Subtracting a number is the same as adding its opposite: a - b = a + (-b).

4Multiplying and Dividing Integers. Same signs give a positive result; different signs give a negative result.

5Number Line Representation. Integers can be visualized on a number line, with positive numbers to the right of zero and negative numbers to the left.

Worked Examples

Evaluate -5 + 8.

Evaluate -7 - 4.

-11

Evaluate (-3) x (-6).

Formulas

a - b = a + (-b)

Practice Yourself

Evaluate -4 + 9.

Evaluate 6 - 10.

-4

Evaluate -3 x 5.

-15