1. How do you use proportions to find unknown values?
Rewrite so the divisor is a whole number:
56.38 ÷ 0.235
Heath needs 1/3 cups of sugar for 1 batch of cookies. How much would he need for 4 batches?

2. Proportions How to check if two ratios are Proportions
Finding the missing number
Using algebra
Finding the missing number
Using equivalent ratios
Finding the missing number
Using cross products

4. How to check if two ratios are proportions
1. Turn both ratios into decimals
2. Simplify both ratios: They should simplify to the same ratio if they are equal
3. Cross Multiply from bottom to top: The products should be the same if they are equal

5. Simplify to check
Use cross products
Use decimals to
check

9. How to find the missing part of a proportion using (algebra)
Proportions
How to find the missing part of a proportion using (algebra)
Step 1: Isolate the variable by doing the opposite operation to both sides.
24/36 = 10/x
Step 2: Simplify your fraction

11. Proportions
How to check if two ratios are proportions
How to find the missing part of a proportion using equivalent ratios
Step 1: Reduce the fraction you have. Then see how you can multiply from one fraction to the other.

13. How to check if two ratios are proportions
How to find the missing part of a proportion using (cross products) Easy
Using cross products is algebra, it just starts a different way, but you end up using algebra to solve.

14. Short Cut for Solving Proportions
If the numerator is missing: Multiply the denominator of the missing numerator by the fraction: your answer is the missing numerator. x/4 = 9/12 = 9/12 * 4 = 3
If the denominator is missing: multiply the numerator of the missing denominator by the reciprocal of the fraction. 3/x = 9/ = 12/9 * 3 = 4

16. Homework: