represent integer operations with concrete models and connect the actions with the models to standardized algorithms

How Do You Figure Out the Sign of a Product or Quotient?

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!
What's a Rational Number?

There are lots of different kind of numbers that you should know about, and that includes rational numbers. Check out the tutorial!
How Do You Rewrite Subtraction as Addition?

Subtracting a positive is the same thing as adding a negative. Subtracting a negative is the same as adding a positive. Get a closer look with this tutorial!
How Do You Add Two Negative Numbers?

Adding two negative numbers together? Just add the absolute value of each number together, put a negative sign in front, and you have your answer! See how it's done in this tutorial.