1. Algebra
Mrs. Hubbard

2. Ratios, Proportions & Percents
Ratio- fraction
Example: ½,
Proportion- two or more equivalent fractions
Example: ½ = 2/4
Percent- per every hundred
Example: ½ = 50%

3. The most commonly used fractions…
Benchmark Fractions
The most commonly used fractions…
Fraction
Decimal
Percent
0.50
50%
1/3
0.333
33.3%
0.25
25%
1/5
0.20
20%
1/6
0.166
16.6%
1/8
0.125
12.5%
1/10
0.10
10%
2/3
0.66
66%
0.75
75%

4. Converting Fractions to Decimals
Take the Top Number and Divide it by the Bottom Number.
(you asked for it, now it’s back.)
Mr. Duey video

5. Converting Decimals to Percents
Move the Decimal Point two places to the Right. Example: Convert 0.50 to a Percent 0.50 = 50.0%

6. Converting Percents to Fractions
Write the number in the Percent, as a number over 100, then Simply if necessary.
Example: 50% = 50/100 = ½
Let’s Try It!

7. you have to do to the bottom what you do to the bottom,
Proportions
When Solving a Proportion problem, just remember…. What you do to the top,
you have to do to the bottom OR
what you do to the bottom,
you have to do to the top.
Let’s Try It!

8. Working With Percents Finding the Percent of a Number
10% Trick: To find 10% of any number, move the decimal point one place to the LEFT. This is a short cut for dividing by 10.
Example: 10% of 20 = 2.0
10% of 25 = 2.5
10% of 888 = 88.8

9. Working With Percents
If you can find 10% of a number, then you can easily find 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%. It’s also easy to find 5%!
Example:
If 10% of 20 = 2
20% of 20 = 4
30% of 20 = 6
You Try It!

10. Working with Percents One percent Strategy
Just like the 10 percent trick, we can use the One Percent Strategy to find 1% of any number.
To Find 1% of any number, move the decimal point over two places to the left. (This is a short cut for dividing by 100)
Example: 1% of 550= 5.50

11. Let’s Look at another Strategy
We can solve Percent problems using a Proportion.
Example: 80% of 30

12. Solving Proportions Answer: X = 24 80% of 30 = 24
Step 1: Cross Multiply.
80 x 30 = 100X
Step 2: Multiply
2400 = 100X
Step 3: Solve
2400 = 100 x 24
Answer: X = 24
80% of 30 = 24

13. Keep up the Great work!