The rules that govern on how to multiply and divide integers are very similar. In this lesson, we will focus on the multiplication of integers.
Rules on How to Multiply Integers
Step 1: Multiply their absolute values.
Step 2: Determine the sign of the final answer (in this case it is called the product because we are multiplying) using the following conditions.
- Condition 1: If the signs of the two numbers are the same, the product is always a positive number.
- Condition 2: If the signs of the two numbers are different, the product is always a negative number.
Examples of Integer Multiplications
Example 1: Multiply the integers below.
First, get the absolute value of each number.
Next, multiply or find the product of the absolute values.
Finally, determine the sign of the final answer. The rule states that if the signs of the two integers are different then the final answer will be negative.
Example 2: Multiply the integers below.
Multiply the absolute values of the two numbers.
Since we are multiplying integers having the same sign, final answer (product) should be positive.
Example 3: Find the product of the three integers below.
We can also multiply three or more integers. We just have to multiply two integers at a time. Let me put a parenthesis to show which two numbers we’re going to multiply first.
The product of +3 and –8 equals − 24. It is negative because the signs are different. Then multiply – 24 by –2 to get +48. Remember, the product of two integers with the same sign is always positive.