Method

Multiplying Integers With the Same Sign

The product of two integers is always positive if and only if the factors have the same sign. This means that when the factors are both positive or both negative, ignore the signs and multiply them as if they were whole numbers. To illustrate this process, consider the following multiplication of integers. -3*(-4) There are two steps to follow when the factors have the same sign.

Verify the Signs of the Factors

If both factors are positive, keep the numbers as they are. On the other hand, if the factors are both negative, ignore the signs of the factors to reduce the multiplication to a multiplication of two positive integers. In this example, the signs of the integers will be removed because both are negative. -3*(-4) ⇕ 3*4 The expression is now a multiplication of two whole numbers.

Find the Product Using a Number Line

The first factor indicates how many intervals will be needed to find the product. The second factor indicates the size of each interval. The intervals are drawn on a number line starting from zero. In this case, 3* 4 indicates that three equal intervals of length 4 are needed.

The endpoint represents the product of the given multiplication of integers with the same sign. 3*4=12 ⇔ -3*(-4)=12 The result of multiplication of integers with the same sign is always positive.

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