Measurement
Imperial vs. Metric
Imperial System
- First defined by the British in the 1800’s
- Lengths: mile, yard, foot, inch
- Canada continues to use the Imperial System when trading with goods with the USA
Metric System
- Most commonly used worldwide (ie: Canada, Europe)
- Lengths: kilometer, meter, centimeter, millimeter
- Canada adopted this system in 1970 to replace the Imperial System
1 Foot ruler
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One inch (not actual size)
– Inch divided into 16 equal parts. – Each tick (vertical stroke) represents one sixteenth of an inch – 1/16″ – Count the ticks to determine the number of sixteenths at various points along the inch Note: the fractions have been “simplified” if required |
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To be able to successfully measure in feet and inches you need to know your twelve times table. The imperial measurement system uses fractions.
You will NOT be converting fractions to decimals. If your calculations include decimals, you have made an error.
Because you are working with fractions, your calculator will not be useful
Tip: When completing any assignments or worksheets, always write down the 12 times table first. This will helps avoid calculation errors when converting inches into feet and inches.
1 foot = 12 inches and/or 12 inches = 1 foot
12 Times Table
- 12 x 1 =
- 12 x 2 =
- 12 x 3 =
- 12 x 4 =
- 12 x 5 =
- 12 x 6 =
- 12 x 7 =
- 12 x 8 =
- 12 x 9 =
- 12 x 10 =
- 12 x 11 =
- 12 x 12 =
For example:
3 ticks = 3/16ths of an inch
5 ticks = 5/16ths of an inch
12 ticks = 12/16ths of an inch
You must remember to simplify your fractions
For example:
12 ticks = 12/16ths of an inch
Divide the numerator and the denominator by 4.
Remember: Whatever you do to the top number you must do to the bottom number
12 divided by 4 = 3
16 divided by 4 = 4
Simplified fraction – 12/16″ = 3/4 of an inch or three quarters of an inch.
Conventions (symbols) how to express inches and feet in your answers
All are correct but we will use the last convention showing only the symbols of feet and inches
1 foot = 1ft = 1′
1 inch = 1in = 1″
Examples:
2 feet and 3 inches will be expressed as follows:
2′ 3″
2 feet 3 and 1/6th of an inch will be expressed as follows
2′ 3 1/16″ The inch mark goes at the very end of the fraction of an inch
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