Measurement
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Introduction to Imperial Units

Lesson

You may or may not know that there are two common systems of measurement: the metric system (e.g. metres, litres and kilograms) and the imperial system.

The imperial system was common in the United Kingdom in the mid-nineteenth century and is still used for some measurements. It is also still used in the United States. So let's get familiar with imperial measurements of length, mass and capacity.

 

Measurements of Lengths

Length of a measure of distance from one point to another. Here are a list of imperial units used to measure length in order from smallest to largest:

  • Inch ("): this is a small unit of measurement. 
  • Foot (ft): $12$12 inches make $1$1 foot. A foot is about as long as a $30$30cm ruler.
  • Yard (yd): a yard is equivalent to $3$3 feet. This is about as long as a guitar.
  • Mile (mi): this is a large unit of measurement. A mile is $1760$1760 yards and is equivalent to about $2000$2000 steps.

 

Measurements of Mass

When we weigh something, we are actually measuring its mass. Mass is a measure of how heavy something is, such as a bag of oranges, a suitcase or even a person. Here are a list of imperial measurement units in order from smallest to largest:

  • Ounce (oz): a slice of bread is about an ounce.
  • Pound (lb): there are $16$16 ounces in a pound. People are generally weighed in pounds.
  • Stone (st): a stone is equivalent to $14$14 pounds. This is not as common but people can be weighed in stones.
  • Ton: $2000$2000 pounds equals $1$1 ton. Tons are used to weigh heavy things like cars, trucks and elephants.

 

Measurements of Capacity

Capacity is a measure of the amount something can contain, for example, how much juice will fit in a bottle. Here are a list of imperial measurement units that relate to capacity in order from smallest to largest:

  • Pint (pt): a pint is a relatively small unit of measurement. A small carton of milk is about a pint.
  • Quart (qt): a quart is $2$2 pints (or a quarter of a gallon). A large bottle of milk or juice, like the one pictured is about a quart.
  • Gallon (gal): a gallon is equivalent to $8$8 pints. The amount of petrol you put in a car is usually measured in gallons.

 

Worked Examples

Question 1

Which imperial units would you use to measure these in?

Choose all appropriate options.

  1. The length of your kitchen at home.

    Inches

    A

    Yards

    B

    Gallons

    C

    Miles

    D

    Feet

    E

    Tons

    F

    Inches

    A

    Yards

    B

    Gallons

    C

    Miles

    D

    Feet

    E

    Tons

    F
  2. The distance from London to New York.

    Feet

    A

    Miles

    B

    Inches

    C

    Stones

    D

    Quarts

    E

    Yards

    F

    Feet

    A

    Miles

    B

    Inches

    C

    Stones

    D

    Quarts

    E

    Yards

    F
  3. The length of a pencil.

    Yards

    A

    Inches

    B

    Miles

    C

    Feet

    D

    Pints

    E

    Ounces

    F

    Yards

    A

    Inches

    B

    Miles

    C

    Feet

    D

    Pints

    E

    Ounces

    F

QUESTION 2

Complete the sentence, choosing the correct imperial unit for the space.

  1. You need $4$4 ________ of flour to make enough biscuits for $6$6 people.

    ounces

    A

    pounds

    B

    stones

    C

    tons

    D

    ounces

    A

    pounds

    B

    stones

    C

    tons

    D
  2. Tom's mother had a baby this week, she weighs about $7$7 ________.

    ounces

    A

    stone

    B

    pounds

    C

    tons

    D

    ounces

    A

    stone

    B

    pounds

    C

    tons

    D
  3. Sarah is fifteen years old, she weighs about $8$8 ______.

    tons

    A

    stone

    B

    pounds

    C

    ounces

    D

    tons

    A

    stone

    B

    pounds

    C

    ounces

    D

QUESTION 3

Complete the sentence, choosing the correct imperial unit(s) for the space.

  1. This carton of milk contains 1 _______.

    pound

    A

    gallon

    B

    ton

    C

    pint

    D

    pound

    A

    gallon

    B

    ton

    C

    pint

    D
  2. David dances a lot. He has to drink about 4 ______ of water every day.

    gallons

    A

    ounces

    B

    pounds

    C

    pints

    D

    gallons

    A

    ounces

    B

    pounds

    C

    pints

    D

 

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