Measuring Length

You can measure the length of ANYTHING!

When we measure length we measure how long something is.

We measure using units of length.These can be non-standard

units………..

……..…or standard units.

Millimetres (mm) Centimetres

(cm)

Metres (m) Kilometres (km)

Comparing units of length

Measuring Length in Centimeters

• The centimeter (cm) is used to measure lengths in the metric system. A smaller unit, the millimeter (mm) is used for more accurate measurements. How long is the paper clip to the neatrest centimeter?

DEVELOPING THE CONCEPT

•We are looking for the length of the pen to the nearest _____________.

The millimeter lines help us determine whether

the pen is closer to ____ or _____ centimeters.

If the pen is less than 5 millimeters from the 3 centimeter line, round down. Round up to the next higher centimeter if the paper clip is 5millimeters or more from the 3-centimeter

line.

Since the pen is _____ millimeters longer thanthe 3- centimeter line, we say that it is ____centimeters long, to the nearest centimeter.

Solution sentence: _____________________________

PRACTICE• Measure each item to the nearest centimeter.

• Circle the best estimate:

- The width of a fingernail a. 10mm b. 100mm c. 10cm - The height of a chair. a. 45mm b. 45cm c. 450

cm - The width of this page.

a. 22mm b. 22cm c. 220cm- The width of a dime. a. 18mm b. 180mm c. 180

cm