Question

journal
explain how to use benchmark percents to order and estimate the value of other percents.
remember
you can use benchmarks percents—1%, 5%, 10%, 25%, 50%, and 100%—to perform mental estimation and calculation of percents.
practice
the students at penncrest middle school sold various products for a fall fundraiser. the table shows the percent of profit the school earned and the total amount sold for each type of product.

product	percent profit	amount sold
wrapping paper	40%	$1200
stationery	50%	$900
calendars	25%	$3120

1 use benchmark percents to calculate the amount of profit the school earned on the sale of each product.
a candy
b wrapping paper
c stationery
d calendars
2 suppose that the students also sold $4500 worth of pens and pencils, which earned a 42% profit. calculate the profit the school earned on pens and pencils.

Explanation:

Part 1: Calculating Profit for Each Product

(a) Candy

Step1: Break 65% into benchmark percents (50% + 10% + 5%)

First, find 50% of $6400: $6400 × 0.5 = $3200
Then, find 10% of $6400: $6400 × 0.1 = $640
Next, find 5% of $6400: $6400 × 0.05 = $320

Step2: Add the results together

$3200 + $640 + $320 = $4160

Step1: Break 40% into benchmark percents (10% × 4)

Find 10% of $1200: $1200 × 0.1 = $120

Step2: Multiply by 4 (since 40% = 10% × 4)

$120 × 4 = $480

Step1: Use 50% benchmark (50% = 0.5)

Find 50% of $900: $900 × 0.5 = $450

Answer:

The profit from candy is $\boldsymbol{\$4160}$.

(b) Wrapping Paper