Warm Up Simplify the following For questions 1-3, State whether your answers are rational or irrational numbers.

Operations with Rational and Irrational Numbers

Practice and Check for Understanding

Dimensional Analysis Using the Conversion Factor Objective: Make unit conversions

Fill in the Missing Numbers 1 foot = _____ inches 1 meter = _____ centimeters 1 pound = _______ ounces 1 minute = ______ seconds 1 hour = ________ minutes 1 day = __________ seconds ,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 ? ft 1lb ? oz 1 pt ? c 1 qt ? pt 1 gal ? qt 1 hr ? min 1 min ? s 1m ? cm 1km ? m

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.

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

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

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? The car traveled 44 feet per second.