1. Multiplying and Dividing Rational Numbers

2. Multiplying Fractions
When multiplying fractions, they do NOT need to have a common denominator.
To multiply two (or more) fractions, multiply across, numerator by numerator and denominator by denominator.
If the answer can be simplified, then simplify it.

3. Simplifying Diagonally
When multiplying fractions, we can simplify the fractions and also simplify diagonally. This isn’t necessary, but it can make the numbers smaller and keep you from simplifying at the end.
You do not have to simplify diagonally, it is just an option. If you are more comfortable, multiply across and simplify at the end.

4. Multiplying Mixed Numbers
To multiply mixed numbers, convert them to improper fractions first.

5. Sign Rules Remember, when multiplying signed numbers...
Positive * Positive =
Positive.
Negative * Negative =
Positive.
Positive * Negative =
Negative.

6. Try These: Multiply
Multiply the following fractions and mixed numbers:

7. Multiplication Word Problems
When solving a multiplication word problem, look for the word “of ”.
Decide what the question is asking. Rewrite as an OF sentence is necessary.
Example:

8. Dividing Fractions
When dividing fractions, they do NOT need to have a common denominator.
To divide two fractions, keep the first fraction, change the operation to multiplication, and flip the second fraction. Keep-Change-Flip
Finish the problem by following the rules for multiplying fractions.

9. Dividing Mixed Numbers
To divide mixed numbers, convert them to improper fractions first.

10. Try These: Divide
Divide the following fractions & mixed numbers:

11. Division Word Problems
When solving a division word problem, you will have to decide which fraction represents the whole group and which fraction represents the part.
You will write the division problem with the whole divided by the part.
Example:

12. Division Word Problems
If the problem isn’t set up with the same units and part/whole doesn’t work, you will have to decide which part is being divided by the other.
Rewrite the sentence the following way:
_______ divided by _________
Example: