# Using the Conversion Factor

## Presentation on theme: "Using the Conversion Factor"— Presentation transcript:

Using the Conversion Factor
Objective: Make unit conversions

Fill in the Missing Numbers
12 1 foot = _____ inches 1 meter = _____ centimeters 1 pound = _______ ounces 1 minute = ______ seconds 1 hour = ________ minutes 1 day = __________ seconds 100 16 60 60 What is the purpose of knowing these facts? Give me some examples. 86,400

Unit conversion factor
A unit conversion factor is a fraction whose numerator and denominator are equivalent measures. Some common unit conversion factors are given below. You can also use the reciprocal of these. 1 ft ? in. 1 yd ? ft 1 mi 1lb ? oz 1 pt ? c 1 qt ? pt 1 gal ? qt 1 hr ? min 1 min ? s 1m ? cm 1km ? m Fill in the blanks for as many as you know. Compare with your neighbor.

Unit conversion factor
A unit conversion factor is a fraction whose numerator and denominator are equivalent measures. Some common unit conversion factors are given below. You can also use the reciprocal of these. Ask for some reciprocals so you know they understand.

Choose a unit conversion factor that…
Introduces the unit you want in the answer Cancels out the original unit so that the one you want is all that is left.

“Canceling” out Words

Practice: Choose the appropriate conversion factor.
Inches to feet Minutes to hours Meters to centimeters

Use the one that will cancel out the units you want to change
Convert 8 yards to feet… Make a decision: What conversion factor will you use? Set up the problem: Multiply the measurement by the conversion factor. Hint! Use the one that will cancel out the units you want to change Solve the problem: Perform the multiplication

A bucket holds 16 quarts. How many gallons of water will fill the bucket? Use a unit conversion factor to convert the units. What are the two conversion factors comparing quarts and gallons? Which one will “cancel” quarts? 16 qt 

You Try it! One bag of apples weighs 64 ounces. How many pounds does it weigh? Darren drank 2 liters of water. How many milliliters of water did he drink?

Making Rate Conversions
Use a unit conversion to convert the units within each rate

Convert 80 miles per hour to feet per hour.
Convert 63,360 feet per hour to miles per hour.

You Try it! Convert 32 feet per second to inches per second.
A craft store charges \$1.75 per foot for lace. How much per yard is this?

Word Problems The average American eats 23 pounds of pizza per year. Find the number of ounces the average American eats per year. The average American eats 368 ounces of pizza per year.

General Math Homework Do Practice worksheet for tomorrow.

How many seconds in an hour?
Word Problems… A car traveled 60 miles on a road in 2 hours. How many feet per second was the car traveling? Hint: Set up the words first. How many seconds in an hour? Once you’ve determined how many seconds in an hour, decide which conversion factor you should use. The car traveled 44 feet per second.

Homework  Complete Practice Worksheet B