Integer Operations for Kids: Add, Subtract, Multiply and Divide Negatives (Grade 7 Math)

Hi, I'm Luna from DoodleBeez. Today we are doing all four operations with integers. Integers are whole numbers and their opposites, like negative three, zero and five. A few simple rules make them easy.

Adding two numbers with the same sign is like walking further in one direction. Negative three plus negative five: add the sizes, three plus five is eight, and keep the negative sign. The answer is negative eight.

When the signs are different, subtract the sizes and keep the sign of the number with the bigger size. Negative seven plus four: seven minus four is three. Seven is bigger and negative, so the answer is negative three.

To subtract an integer, add its opposite. Five minus negative three becomes five plus three, which is eight. Negative two minus six becomes negative two plus negative six, which is negative eight.

Multiplying and dividing use the same sign rule. If the signs are the same, the answer is positive. If the signs are different, the answer is negative. Negative four times negative six is twenty four. Negative twenty divided by five is negative four.

Integers show up in real life. In the morning the temperature is negative six degrees. By lunch it rises nine degrees. Negative six plus nine is positive three, so it is now three degrees.

Now it's your turn. Work out negative nine plus fifteen, and negative three times seven. Pause and try. Negative nine plus fifteen is six. Negative three times seven is negative twenty one.

Great job! Remember, same signs add and keep the sign, different signs subtract, subtracting means adding the opposite, and for times and divide, same signs give a positive. Practice integer operations in Middle School Math at doodlebeez.com. See you next time!