Math Word Problems Demystified - A Self Teaching Guide

(Marvins-Underground-K-12) #1

IMPLEMENTATION: Solve the proportion.


4 gallons
1120 sq:ft:

¼

7 gallons
xsq:ft:

1120  7 ¼ 4 x

7840 ¼ 4 x

7840
4

¼

41 x
41

1960 square feet ¼x

7 gallons will cover 1960 square feet.


EVALUATION:


4

1120

¼

7

1960

1120  7 ¼ 4  1960

7840 ¼ 7840

EXAMPLE:If the scale on a map reads 2 inches¼50 miles, how many miles
are there between two cities whose distance on a map is 7.5 inches?


SOLUTION:


GOAL: You are being asked to find the distance between two cities.


STRATEGY: The ratio statement is2 inches50 miles. The proportion is50 miles2in: ¼x^7 :miles5in:.


LESSON 6 Using Proportions 55

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