Big Ideas Math: Modeling Real Life, Grade 7
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Exercise 25 Page 274

Is the value of the new amount greater than or less than the value of the original amount?

Decrease or Increase? Decrease
Percent of Change: about 56.6 %

Practice makes perfect

We want to tell whether each percent change is an increase or decrease. Then, we want to find the percent change. Let's do it one at a time.

Percent Increase or Percent Decrease

Recall that if a new amount is greater than the original amount, the percent change is called a percent increase. If the new amount is less than the original amount, the percent change is called a percent decrease. Consider the given amounts. Original Amount:&120 meals New Amount:&52 mealsWe can see that the new amount is less than the original amount, so the percent change is a decrease.

Finding the Percent Change

To determine the percent change p, we can use the following general formula. p % =Amount of change/Original amount From the given values, we can see the original amount was 120 and the new amount is 52. This is a decrease in the amount. Let's find the amount of decrease. 120- 52= 68 The difference between the original amount and the new amount is 68. Now we can use the formula.

Percent of change=Amount of decrease/Original amount
Percent of change=68/120
Percent of change=17/30
Percent of change=0.566666...
Percent of change ≈ 0.566
Percent of change = 56.6 %

The percent decrease is about 56.6 %.