7th Grade Math

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Convert Measurements

PART A BCDE

Multi-Part

Lesson 1

F

GLE 0706.4.2

Apply proportionality to

converting among different

units of measurements to

solve problems involving

rates such as motion at a

constant speed.

GLE 0706.4.4 Understand

and use ratios, derived

quantities, and indirect

measurements.

Lesson 1E Convert Measurements 639

Main Idea

Convert units of

measure between

derived units to solve

problems.

Vocabulary

derived unit

Convert Rates

TRAINS Some of the fastest passenger trains are located in Japan and

France. The table shows various trains and their speeds.

Shinkansen

TGV

AMTRAK

300

300 – 320

200

186

186 – 199

124

Japan

France

United

States

Train Country

Metric Unit

(kilometers

per hour)

Customary

Unit (miles

per hour)

1. How many feet are in one mile?


2. How many seconds are in one hour?

You can convert one rate to an equivalent rate by multiplying by a

unit ratio or its reciprocal. A derived unit is a unit that is derived

from a measurement system base unit such as length, mass, or time.

Examples include square inches and meters per second.

Convert Rates

FISH A swordfish can swim at a rate of 60 miles per hour. How

many feet per hour is this?

You can use 1 mile = 5,280 feet to convert the rates.

_60 mi

1 h

= _60 mi

1 h

· _5,280 ft

1 mi

Multiply by _5,280 ft1 mi.

= _60 mi

1 h

· _5,280 ft

1 mi

Divide out common units.

= _^60 · 5,280 ft

1 · 1 h

Simplify.

= _316,800 ft

1 h

Simplify.

A swordfish can swim at a rate of 316,800 feet per hour.

a. BIRDS A gull can fly at a speed of 22 miles per hour. About how

many kilometers per hour can the gull fly?

V

d

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