Docstoc

mod8-les2-how-to-read-ruler

Document Sample
mod8-les2-how-to-read-ruler Powered By Docstoc
					                                                       Consumer Math 30S Module
                                                                                   8



                        How to Read an Imperial Ruler

The standard imperial ruler or tape measure is divided up into feet and inches. Each foot
is divided into 12 inches. Each inch is divided into smaller units which are referred to as
fractions of an inch. If you can read those subdivisions, you won’t have a problem
reading the ruler when measuring.




Subdivisions of an Inch

In each inch there are a number of lines of different lengths as you can see above.
There are lines marking 1/16, 1/8, ¼, and ½ of an inch. Note that when writing inches or
portions of an inch the quote symbol (“) is used. A good visual guide to follow is the
longer the length of the line, the larger the unit of measurement.

The longest vertical line is the line to mark each inch. Within the inch, the lines are
broken down into the following:

      In the middle is the half-inch mark (1/2”) and there is only one.
      The next longest line is the one quarter of an inch mark (1/4”) and there are two.
      The next longest line is the one eighth of an inch mark (1/8”) and there are four.
      The next longest line is the one sixteenth of an inch mark (1/16”) and there are
       eight.



                                                                                 Page 1 of 5
                                                      Consumer Math 30S Module
                                                                                 8

On the typical ruler the basic (smallest) unit of measurement is 1/16". If you count the
lines between the start of an inch and where the inch notation is (for example above 1”)
there are sixteen lines. This is because an inch is 16/16th of an inch long.

In mathematics we like to express fractional numbers in the largest unit possible.
Therefore, we call 16/16th of an inch 1 inch. If you are measuring something and you
count 8 lines that would be 8/16” or half an inch which would be expressed as ½”. If
you are measuring something and you count four lines that would be 4/16” or a quarter
of an inch or ¼”.

(Source: http://www.woodzone.com/articles/Read_A_Ruler.htm)


There are websites you can visit to practice what you know about reading a ruler.


Website #1

http://www.manawa.k12.wi.us/LWHS/Staff/Staff/Kelly%20Koller/General%20Tutorials/
How%20to%20read%20a%20ruler.htm

This is a video presentation which reviews your knowledge about fractions. It transfers
the knowledge you have about fractions and shows fractions of an inch and the
markings or lines that make up an inch on a ruler.


Website #2

http://rickyspears.com/rulergame/

The Ruler Game is an interactive game where you can test your knowledge about
reading ruler markings. There is a START NEW GAME button below the 4 inch ruler.
When the game is activated you will be given a measurement to find on the ruler. Move
your mouse over the ruled lines which will highlight to green. Left click to make your
selection. If you get it wrong a large red X will appear on the ruler. If you get it right,
you can continue with the game.




                                                                                Page 2 of 5
                                                                 Consumer Math 30S Module
                                                                                              8



                                   How to Read a Metric Ruler
Metric rulers, in comparison to imperial rulers, are fairly easy to read. The metric ruler is
divided into units called centimetres and millimetres only. The numbers on the metric
ruler represent the centimetres and are noted with the longest vertical line.




The smallest lines represent the millimeters. There are 10 millimetres for each
centimetre. If you measure 7 marks after a centimeter, it is 1.7 centimeters long.

(Source: http://www.onlineconversion.com/faq_05.htm)

Answers to Practice Activity

A – 15/16”          B – 2”             C – 3 ¼”                 D – 4 1/8”             E – 5 7/16”

F – .9 cm or 9 mm              G – 4.4 cm or 44 mm   H – 8 cm            I – 10.5 cm


There are websites you can visit to practice what you know about reading a ruler.


Website #1
http://www.wisc-online.com/objects/index_tj.asp?objID=ABM4202
This is an interactive site where you can practice reading and finding metric
measurements in centimeters, millimeters and meters.


Website #2

http://www.funbrain.com/measure/\

This is interactive game with three levels of difficulty using the metric system or the
imperial system. For the metric system, you are given a metric ruler with a red line and
4 possible answers. As you click on the correct answer, your score is tallied. The easy
version only shows centimeters. The hardest version shows portions of centimeters.




                                                                                            Page 3 of 5
                                                                    Consumer Math 30S Module
                                                                                      8

Website #3

http://www.wsd1.org/waec/math/Consumer%20Math%20Advanced/Unit%202%
20Design%20and%20Measurement/Ruler%20Meas/measmain.htm

This site demonstrates the actual measure at each vertical line on the ruler for the
metric and imperial systems.

Practice Activity
Record your answers for the precise location of each letter in the table below. Note
whether the measurement is “(for inches) or cm/mm (for centimeters or millimeters) in
your answer.




Source: http://www.coolschool.ca/lor/EMA11/unit4/U04L02/read-ruler.htm#


         A                       B                       C                D           E


         F                       G                      H                 I




                                                                                     Page 4 of 5
                                                                Consumer Math 30S Module
                                                                                                 8

Check your answers by looking for a similar table on the previous page. If your answer isn’t exactly the
same, review this with a classmate or proctor.




                                                                                               Page 5 of 5

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:34
posted:12/4/2011
language:English
pages:5