### Metric Units of Length

milli - means thousandth

1mm = 0.001m

1m=1,000mm

centi - means hundredth

1cm = 0.01m

1m = 100cm

kilo - means thousand

1km = 1,000m

1m = 0.001km

### Metric Units of Mass and Capacity

Metric Units of Mass:

1kg = 1,000g

0.001 kg = 1g

1g = 1,000mg

0.001g = 1mg

Metric Units of Capacity

1kL = 1.000L

0.001 kL = 1L

1L = 1,000 mL

0.001L = 1mL

### Converting Units in the Customary System

Length:

1foot (ft) = 12 inches (in)

1 yard (yd) = 3 feet (ft)

1 mile (mi) = 5,280 feet (ft)

Weight:

1 pound (lb) = 16 ounces (oz)

Liquid Capacity:

1 gallon (gal) = 4 quarts (qt)

1 quart = 2 pints (pt)

1 pint (pt) = 2 cups (c)

### Converting Between Measurement Systems

Length:

1 in ≈ 2.54 cm

1 km ≈ 0.62mi

Area:

1 in² ≈ 6.45 cm²

Volume:

1 in³ ≈ 16.39 cm³

Capacity:

1 L ≈ 1.06 qt

Weight:

1 oz ≈ 28 g

1 kg ≈ 2.2 lb

### Computing with Customary Measures

When you solve problems with customary units of measure, you must change the units of measurement.

### Perimeter

To find the perimeter of a given geometric figure, you add the lengths of the sides.

Example:

Find missing lengths.

8 - 7 = 1

4 - 1 = 3

x = 3 ft

3 + 3 = 6

8 - 6 = 2

y = 2 ft

8 + 7 + 3 + 3 + 2 + 4 + 3 + 8 = 38

Perimeter = 38 ft

### Area of Rectangles and Squares

Area = Base x Height

The area is expressed in square + unit such as square inches (in²), square feet (ft²), or square centimeter (cm²).

### Circle

The diameter of a circle is the distance across the circle through its center.

The radius is the distance from the center to any point on the circle.

### Surface Area of Triangular Prisms

Triangular prisms has two of the same sizes for the top and the base. Find areas of the three rectangular shape sizes. Add them together.

### Surface Area of Cylinders

1. Find areas of circle. A = π x r²

2. Multiply circle's area by two. (Top + Base)

3. Find area of rectangle.

4. Add them together.

Example:

Area of circle = 3.14 x 2² = 12.56

Area of circles = 12.56 x 2 =25.12

Base of rectangle = 3.14 x 4 =12.56

Area of rectangle = 12.56 x 5 = 62.80

Area of cylinder = 25.12 + 62.80 = 87.92 in²

### Volume of Triangular Prisms

Base = Triangle

Area of Triangle = (Base x Height) ÷ 2

Volume = Area of triangle x height