1. Converting Customary Units Using Proportions

2.   Proportion: a balanced equation that shows the relationship among various quantities.  Fractions with equal cross products Vocabulary

3.   Same labels go on the same line  1 st fraction contains the conversion key  2 nd fraction contains information from the problem From key From problem 1 pound = 4 pounds 16 ounces x ounces Helpful hints to convert with proportions

4.  Conversion Key: 1 pound = 16 ounces 1 ton = 2,000 pounds 1. A box weighs 32 oz. How many pounds is that? From key From problem Proportion: = Cross products: 16(x) = 32(1) Guided Practice 1 pound 16 ounces X pounds 32 ounces

5.   CHECK FOR REASONABLENESS Small to large unit = smaller answer Check

6.  Conversion Key: 1 pound = 16 ounces 1 ton = 2,000 pounds 2. A bag of rice weighs 60 oz. How many pounds is that? From key From problem Proportion: = Cross products: 16(x) = 60(1) Guided Practice 1 pound 16 ounces X pounds 60 ounces

7.   CHECK FOR REASONABLENESS Small to large unit = smaller answer Check

8.   A monkey weighs 13 pounds. How many ounces is that?  The SWAT team van weighs 6 tons. How many pound is that? Try on your own

9.   1 st fraction: conversion chart  2 nd fraction: info in problem  Calculate cross products and solve for variable  Check for reasonableness Independent Practice