Lesson 1: Measurement Systems - Metric Rulers

   Constructing Knowledge

You are probably familiar with some instruments for measuring distances. Take a minute, and list some familiar instruments used to measure distance.

When you made a list of distance measuring instruments, there is a good chance you included a ruler, metre stick, or tape measure. All three of those instruments are very similar. In this lesson, you will focus on measuring using a ruler, but the skills acquired will be helpful when using metre sticks and tape measures too.

Rulers


A common style of ruler shows 15 centimetres on one side and 6 inches on the other.


Metric Rulers


The centimetre side of this ruler shows 10 lines per centimetre, which means the lines are 1/10 cm, or 0.1 cm, apart. You can also interpret this ruler as having lines that are 1 mm apart since 1 mm = 0.1 cm. To measure an object using the ruler, line up one end of the object with the 0 mark, and read the length measurement at the other end of the object.

EXAMPLE 1

State the length of the rectangle shown in the diagram.



Solution


The rectangle goes two lines past 6 cm. This rectangle is 6.2 cm, or 62 mm, long.


Now, it is your turn! Complete the questions in your Chapter 5, Lesson 1 Practice Makes Perfect that refer to Metric Rulers.



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