Imperial Conversions

Ch. 3 Measurement

The Imperial system was developed in ancient Rome based on referents from the human body and everyday activities.

A referent is a known measure used for comparing and estimating.

When measuring length with the imperial system, the following units are used:

Inch (in. or “)

Foot (ft or ‘) 12 inches = 1 foot

Yard (yd) 3 feet = 1 yard

Mile (mi) 1760 yards = 1 mile

The following chart may be helpful when converting between Imperial units:

Ex1. Taylor is buying fabric for her graduation dress. Her dress pattern is in inches, but the fabric store only sells in yards. How many inches are there in one yard?

We HAVE yards we WANT inches

Use the conversion chart to move from yards to inches:

1 yard x 3 x 12 = 36 inchesfeet

yard

inches

foot

Ex2. Russell wants to determine how far away the cafeteria is from Mrs. Lin’s classroom in miles. He counts 1584 feet from the classroom to the cafeteria doors. How far is it in miles?

We HAVE feet we WANT miles

Use the conversion chart to move from feet to miles:

1584 feet 3 1760 = 0.3 miles

Sometimes measurements will include feet and inches. If we want to convert to one unit only (either feet or inches) we must change one of the measurements to the desired unit.

Ex3. Tristan is 5’11” tall. How tall is Tristan in inches? We know that 5’ = 5 feet and 11” = 11

inches. We WANT inches so we must convert 5 feet into inches first.

5 feet x 12 = 60 inches

We can now add the 11 inches to determine Tristan’s height in inches.

60 inches + 11 inches = 71 inches total

We also have to consider that inches are divided into 16 parts.

This means we will also have to occasionally add, subtract, and multiply fractions when working with the Imperial system of measurement.

Ex4. Janet wants to build steps up to her porch. There will be six steps, with each step measuring 7 inches high. What will the height of the staircase be in feet and inches?

First we will consider the whole number inches.

7 inches x 6 steps = 42 inches

Next, we will consider the fraction of inches.

*Remember, when MULTIPLYING fractions, we multiply the numerators together, and the denominators together. We then change the fraction to a decimal or a reduced fraction.

x 6 = = 1.5 inch or 1 inches1

46

41

2

Now, combine the two measurements:

42 inches + 1.5 inches = 43.5 inches

Next, we will convert to feet

43.5 inches 12 = 3 feet with a remainder of 0.625

The very last step is to convert the remainder BACK to inches.

0.625 x 12 = 7.5 inches OR 7 inches

The height of the stairs is 3’7 ”

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