Module 5: Solving Problems Involving Percent
Lesson 1: Solving Problems Involving Percent of Increase or Decrease
Two children leave for school. One leaves fifteen minutes before the other; however, they cross each other in the school parking lot. Which child is nearer to the school?
Both the children are at the same distance from their school, as they are at the same place at the same time.
Add the following numbers:
1.) 1.2359 + 9.01235 = ___________
2.) 0.17896 + 0.75489 = ___________
3.) 87.1496 + 6.87542 = ___________
4.) 0.88963 + 1.24796 = ___________
5.) 67.1254 + 0.9752 = ___________
10.24825
0.93385
94.02502
1.86483
68.1006
A ratio can be written in three different ways such as:
word form → a is to b
colon form → a : b
Ratio is the spoken language of arithmetic. It is a way of comparing two or more quantities having the same units.
| WORD FORM | COLON FORM | FRACTION FORM |
5 and 7 | | | |
11 and 19 | | | |
21 and 23 | | | |
34 and 41 | | | |
101 and 102 | | | |
A proportion is an equation that says one ratio is equal to another
A proportion is an equation stating that two ratios are equal
2:3 = 4:6
Parts of Proportion
Means
Extremes
2:3 = 4:6
12
12
Write proportion or not proportion.
Equation | Solution | Answer |
1.) 2 is to 3 and 6 is to 12 | | |
2.) 3 is to 5 and 9 is to 15 | | |
3.) 4 is to 6 and 5 is to 7 | | |
4.) 5 is to 7 and 10 is to 14 | | |
5.) 6 is to 8 and 12 is to 24 | | |
Statement | Base | Rate | Percentage |
2% of 30 is 0.6 | 30 | 2% | 0.6 |
1. 10 is 50% of 20 | | | |
2. 25% of 100 is 25 | | | |
3. 6% of 700 is 42 | | | |
4. 80% of 50 is 40 | | | |
5. 15 is 10% of 150 | | | |
Identify the base, rate, and percentage by completing the table below. The first one is done for you.
Conversion of Percent to Decimals to Fraction
Percent | Decimals | Fraction |
25% | .25 | |
| .45 | |
| | |
| .99 | |
27% | | |
100% | | |
What is PRB
What is the formula of Percent
What is the formula of rate?
What is the formula of base?
PRB- Percentage, Rate and Base
P=RxB
Identify whether the missing value is the percentage, base, or rate. Then, find each missing value.
1.) 12% of 72 is what number?= ___________
2.) 20 is what percent of 80? = ___________
3.) What percent of 48 is 6? = ___________
4.) 8% of a number is 15.6 = ___________
5.) What is 6% of 400? = ___________
8.64
25%
12.5%
1.248
24
What is PRB
What is the formula in finding Percentage?
Percentage, Rate and Base
P = R x B
What is the formula in finding Rate?
What is the formula in finding base?
Johnny bought a computer printer on sale at the store. The computer printer was originally sold at ₱9 000 last month and it is now on sale at ₱7 650. What is the percent of change?
Understand
What are the given numbers?
What is asked?
Plan
Think: What is the difference between the original price and the sale price?
What percent of the original price is the difference?
Solve
Answer
Percent of Change
Percent of Change Indicates how much a quantity increases or decreases with respect to the original amount.
Last week, oil price was set at ₱30.00 per liter. This week, it became ₱32.00 per liter. Find the percent of increase in the oil price.
Answer
Steps:
Understand
What are the given numbers?
What is asked?
Solve
New Price – Original Price
________ - ___________
Price Difference= _________
Percent of Increase =Price Difference x 100%
Original Price
Percent of Increase: _________________
Last week, oil price was set at ₱30.00 per liter. This week, it became ₱32.00 per liter. Find the percent of increase in the oil price.
Steps:
Understand
What are the given numbers?
What is asked?
Solve
Answer
New Price – Original Price
________ - ___________
Price Difference= _________
Percent of Increase =Price Difference x 100%
Original Price
Percent of Increase: _________________