Customary Units of Capacity

What is capacity?

The measure of how much liquid or other pourable substance a container will hold.
OR
How much of a liquid or pourable substance there is.

What are the customary units of capacity?

Cups (c) – Small glass of juice.
Pints (pt) – Large water glass.
Quarts (qt) – Large thermos.
Gallons (gal) – Large container of milk.

8 Fluid Ounces (fl oz) = 1 Cup (c)
2 Cups = 1 Pint (pt)
2 Pints = 1 Quart (qt)
4 Quarts = 1 Gallon (gl)


How do we convert between units of customary capacity?

If you are converting from a larger unit to a smaller unit – multiply.
If you are converting from a smaller unit to a larger unit – divide.

Example:
18 Quarts (qt) = ? Pints (pt)
Quarts are bigger than Pints – so you are going to multiply.
Think about what you already know – 2 Pints (pt) = 1 Quart (qt)
18 x 2 = 36
18 Quarts (qt) = 36 Pints (pt)

Example:
? Pints (pt) = 6 Cups (c)
Cups are smaller than Pints - so you are going to divide.
Think about what you already know - 2 Cups (pt) = 1 Pint
6/2 = 3
3 Pints (pt) = 6 Cups (c)

Metric Units of Capacity

What are the metric units of capacity?

Milliliter (ml) – Eyedropper
Liter (L) – Larger plastic bottle of soda.

1,000 Milliliters (ml) = 1 Liter (L)

How do we convert between units of metric capacity?

If you are converting from a larger unit to a smaller unit – multiply.
If you are converting from a smaller unit to a larger unit – divide.

Example:
8.8 Liters (L) = ? Milliliter (ml)
Liters (L) are bigger than Milliliters (ml) so you are going to multiply.
Think about what you already know – 1,000 Milliliters (ml) = 1 Liter (L),
8.8 x 1,000 = 8,800Milliliters (ml)

Example:
9,500 Milliliters (ml) = ? Liters (L)
Millimeters (ml) are smaller than Liters (L) so you are going to divide.
Think about what you already know – 1 Liter(L) = 1,000 Milliliters (ml)
9,500/1,000 = 9.5 Liters (L)