Converting Measures

Lesson 5 (4th 6 Weeks)TEKS 6.4A & 6.8D

Using a ratio (proportion) table or T-chart to represent relationships

between measures

1. Organize the data in a table/chartInches Feet

12 1

24 2

36 3

48 4

x y

(# of inches ÷ by 12 = # of feet)

2. Look for a relationship between the measures.

3. Check the rule to determine whether it satisfies all remaining pairs of numbers.

Inches Process Feet

12 1

24 2

36 3

48 4

x y

12 ÷ 12 = 124 ÷ 12 = 236 ÷ 12 = 348 ÷ 12 = 4x ÷ 12 = y

Let x represent the number of inches and y represent the number of feet.

4. Write an equation or expression using variables to represent the relationship.

Inches Process Feet

12 1

24 2

36 3

48 4

x y

12 ÷ 12 = 1

24 ÷ 12 = 2

36 ÷ 12 = 3

48 ÷ 12 = 4x ÷ 12 = y

Equations: x ÷ 12 = y or y = x ÷ 12

Expression: x ÷ 12

Using Proportions to Convert Measures

EX: 12 pints = ______ quarts

1. Use your 6th grade mathematics chart and write the relationship between the measures as a ratio in fraction form.

x

1 quart = 2 pints

1

2

quartpint

2. Set up a proportion with the known measurement.

3. Solve for the unknown.

1

2

quartpint

12x

1

2

quartpint 12

x

• 6 =

• 6 =

6

EX: 233 milliliters = _______ liter

1. Use your 6th grade mathematics chart and write the relationship between the measure.

2. Let’s write what we know right above what we just wrote.

1 liter = 1000 milliliters

1 liter = 1000 milliliters

? liter = 233 milliliters

3. Notice how the milliliters forms a fraction. We can write the fraction as a decimal.

1 liter = 1000 milliliters

? liter = 233 milliliters

0.233 liters