How can we use the concept:
The ratio between meters and feet is: 1 meter : 3.28084 feet.
3.28084 is a difficult number to calculate with. It can be rounded but the more rounding is used, the less accurate the answer is. An inch is exactly 2.54 centimeters so the best practice when converting between metric and customary length measurements is to convert to centimeters or inches and switch measurement systems using the ratio 1 inch : 2.54 centimeters.
When measurement ratios are written as fractions, units in the denominators will cancel out the same unit in the numerator.
An organizational technique for converting measurements is to write all the needed ratios as fractions. Line up and flip the fractions so that unneeded units are cancelled out and the desired units are left in the numerator.
Example: Convert 6 meters to feet
Start with 6 meters
Meters is in the unit in the numerator, meters won’t be in the answer so it needs to be cancelled. The ratio that has meters is
. Since meters is currently in the numerator, this ratio will be left as is so that the meter in the denominator cancels the one in the numerator.
Now that meters have been cancelled the only unit we have is centimeters. Centimeters is not the unit needed so it also needs to be cancelled. The ratio that has centimeters is
Centimeters are already in the numerator so this ratio needs to be flipped to
so that the centimeters will cancel out.
Sample Math Problems
1. Convert 13 meters to feet using the rounded ratio
Solution: 13 meters x
