A positive times a positive is a positive. A negative times a negative is a positive. What about a negative times a positive? This tutorial gives you the answer by showing you how multiply (and divide!) with mixed signs.
Multiplying and dividing numbers takes a good amount of thinking, and it's easy to make a mistake. But you can make sure that you're on the right track if you check whether the answer should be positive or negative. In this tutorial you'll see exactly how to tell if your answer will be positive or negative, even if you don't know the exact value of the answer. That way you'll always be able to check your answers!
Multiplying integers is just like performing a bunch of additions of the same integer! Check out this tutorial and see how much multiplying and repeated addition have in common.