Grade 7: The Learning Equation Math
12.07 Percent
|
Refresher pp 36-7 |
The student will:
Percent ReviewEstimating Percent - visual and interactive You can model percent with a 100 square grid. Click on the grey/red squares to increase/decrease the percent!! Remember a percent (%) can be written as fraction with a denominator of 100.
|
||
| Percent | 23 : 100 = 23% 32/100 = 32% |
a ratio whose second term is 100. Percent means "parts per hundred". We use the symbol /100 or % for percent. |
| Converting Fractions to Percent | 3/4 = 75/100 = 75% 2/5 = 40/100 = 40% 3/10 = 30/100 = 30% 9/20 = 45/100 = 45% |
use equivalent fractions, if the denominator is a factor of 100. |
| Converting Percent to Fractions | 75% = 75/100 = 3/4 40% = 40/100 = 2/5 30% = 30/100 = 3/10 45% = 45/100 = 9/20 |
Change percent to a fraction with a denominatorof 100.
Reduce to lowest terms. Quia - Matching - Percent - Fraction Match
|
| Converting Fractions to Decimals | 2/3 = 0.666... 15/9 = 1.555... |
divide the numerator by the denominator if the denominator of the fraction is not a factor of 100. |
| Converting Decimals to Fractions | 0.84 = 84/100 = 21/25 1.43 = 1 43/100 |
Make sure there is at least two decimal places. Move
the decimal to the end of the hundredth digit and then place this number over 100.
Reduce to lowest terms. If there are more than two decimal places, then move the decimal to the end of the last digit, then place the number over the following denominators: 3 decimal places --> /1000 4 decimal places --> /10 000 Quia - Matching - Fraction Decimal Conversion
|
0.333... = 3/9 0.666... = 6/9 = 2/3 1.555... = 1 5/9 |
For this course, the limit is single-digit nonterminating
decimals. The denominator for these fractions is 9. Reduce to lowest terms. Quia - Concentration - Fraction Decimal Conversion
|
|
| Converting Decimals to Percent | 0.005 = 0.5% 0.23 = 23% 0.67 = 67% 2.17 = 217% 3.456 = 345.6% |
multiply the decimal by 100 to change the decimal to a percent. |
| Converting Percent to Decimals | 0.5% = 0.005 23% = 0.23 67% = 0.67 217% = 2.17 345.6% = 3.456 |
divide the percent by 100 to change the percent to a decimal |
Percent Problem TypesYou can use the following to answer several types of percent problems. The format for word problems is often:
What % of (number) is what? Let's examine two methods of solving this type of word problem.
There are 3 types of word problem you will encounter. We can apply both methods shown to solve these problems. Study the samples below to learn both methods.
|
|||||
5% of 300 is what? Method 1: 5% of 300 is what? x% x of = is 5% x 300 = i 0.05 x 300 = i i = 15
Method 2: 5% of 300 is what? 5/100 = i/300 Cross-multiply to solve: 100 x i = 5 x 300 100 i = 1500 i = 15
|
50% of what is 40? Method 1: 50% of what is 40? 50% x o = 40 0.5 o = 40 o = 80
Method 2: 50% of what is 40? 50/100 = 40/o Cross-multiply to solve: 50 x o = 100 x 40 50 o = 4000 o = 80
|
What % of 80 is 60? Method 1: What % of 80 is 60? x% x 80 = 60 x% = 60/80 = 0.75 x = 75%
Method 2: What % of 80 is 60? x/100 = 60/80 Cross-multiply to solve: 80x = 100 x 60 80x = 6000 x = 75%
|
|||
Estimating Percents |
|
| 10% Relationships | 1% Relationships |
| A store is offering a 30% discount on pants. If the regular price
for a pair of pants is $49.99, how much discount will you get? 10% Estimate: 10% of $50 is $5 30% Estimate: The discount will be about $15. |
A pizza place is offering a7% discount on medium pizza.. If the
regular price for the pizza is $9.99, how much discount will you get? 1% Estimate: 1% of $10 is $0.10 70% Estimate: The discount will be about $0.70 |
Algebra.help -- Percentage Calculators
Algebra.help -- Percentage Calculator - Word Translation method
Lesson on The Meaning Of Percent
Converting Percentages to Fractions
Solve Ratio and Percent Problems
percent, estimate, numerator, denominator, rounded, circle, graph, survey
Click on the squares to add and subtract them from the grid with 100 squares.. The numerator of the fraction, when the denominator is 100 represents percent.
Lessons on Understanding Percent
Multiplying of Decimals: Grade 7: Lesson 12.01
Division of Decimals: Grade 7 Lesson 12.02
Lessons on Understanding Percent
Fraction Conversions: Grade 7 Lesson 11.05
Decimal Conversions: Grade 7 Lesson 11.06
included in Percent Review
- Comments to: Jim Reed
- Started September, 1998. Copyright © 1999, 2000
visitors since September 3, 2000