Wonderlic Mathematics Review: Positive and Negative Numbers

A precursor to working with negative numbers is understanding what absolute values are.

A number’s absolute value is simply the distance away from zero a number is on the number line.

The absolute value of a number is always positive and is written .

For example, the absolute value of 3, written as , is 3 because the distance between 0 and 3 on a number line is three units.

Likewise, the absolute value of –3, written as  is 3 because the distance between 0 and –3 on a number line is three units. So .


When adding signed numbers, if the signs are the same simply add the absolute values of the addends and apply the original sign to the sum.

For example,  and .

When the original signs are different, take the absolute values of the addends and subtract the smaller value from the larger value, then apply the original sign of the larger value to the difference. For instance,  and .

For subtracting signed numbers, change the sign of the number after the minus symbol and then follow the same rules used for addition.

For example, .

If the signs are the same the product is positive when multiplying signed numbers.

For example,  and .

If the signs are opposite, the product is negative.

For example,  and .

When more than two factors are multiplied together, the sign of the product is determined by how many negative factors are present.

If there are an odd number of negative factors then the product is negative, whereas an even number of negative factors indicates a positive product.

For instance,  and .

The rules for dividing signed numbers are similar to multiplying signed numbers.

If the dividend and divisor have the same sign, the quotient is positive.

If the dividend and divisor have opposite signs, the quotient is negative. For example, .