Unit 6: Measurement
Topic C: Measuring
Measuring Distance and Length
The metre is the base unit for this purpose. In Topic C, all the prefixes were combined with the base unit metre. But for everyday purposes, we use only kilo, centi, and milli with metre.
| Use… | To Measure… |
|---|---|
| kilometres | long distances, such as road distances, length of rivers, to measure car speed per hour, highway signs. |
| metres | medium lengths, such as room size, track and field events, size of building lots, rope, extension cords, fabric, carpeting. |
| centimetres | common, smaller things such as a person’s height, waist measurement, size of furniture, length of pants, width of wax paper, shoelaces, skis. |
| millimetres | very small things such as postage stamps, size of precise tools, length of screws and nails, fine sewing measurements, thickness of plywood and glass. |
Exercise 1
Get a metre stick or tape measure. If you have problems, your instructor will assist you in reading the measuring tool that you use and will check your work.
- Find the centimetre markings on the metre stick or tape measure. Remember that one centimetre is one hundredth of a metre, so there are 100 centimetres in each metre.
- Using the centimetre markings, measure the following:
- your desk or table top, in both directions
- the distance from the floor to your desk top (its height)
- the cover of this book
- the covers of two different-sized books
- the thickness of a fat dictionary
- the height of your chair seat from the floor
Your hand span is a handy measurement to know because you can use it as a measuring tool to make quick measurements of smaller objects. Knowing the length of your pace is also useful for quick measurements of room size, etc.
- You will need a flexible tape measure for these measurements to be taken in centimetres.
- your height
- your foot length
- your smile
- ear to ear
- around your head
- the length of your arm
Exercise 2
The answers to questions a are listed below. Your instructor will check your other measurements and assist you as needed.
- Look carefully at the measuring tool you have been using. Find the millimetre markings if they have been written on the tape or stick. You may have to look at a shorter ruler to find the millimetres marked.
- A millimetre is one thousandth of a metre.
- millimetres equal one metre.
- millimetres equal one centimetre.
- Now measure these items in your classroom, first in centimetres and then in millimetres:
- the length of a pen
- the length of a pencil
- the length of an eraser
- the length of two different pieces of chalk
- the length of your longest fingernail
- the width of the fingernail on your small finger
- Measure the longest (or widest) part of each picture in cm and in mm.
Answers to Exercise 2
-
- A millimetre is one thousandth of a metre.
- 1000 millimetres equal one metre.
- 10 millimetres equal one centimetre.
Exercise 3
Make the following measurements. Choose the most convenient unit (metres,