What would you like to measure?
Distance:
Distance is the number that represents how far apart two objects are.
Units of Distance Include (but are not limited to):
American:
Inches-in
A pencil is an example of something you would measure in inches. Can you estimate how long an unsharpened pencil is? You probably can if you can use perspective. Think about this: The distance on your index finger, from the first to the second knuckle, is about an inch. How many times do you think you could fit the distance between your knuckles in the length of the pencil?
Feet-ft
A desk is something that can be measured in feet. One foot is twelve inches. It would take too much time to measure something this size with your knuckles right? So instead, estimate the length of your desk by thinking that the distance from your wrist to elbow is about a foot. Of course this isn't exact, but you are just estimating, and to estimate you need perspective so you can judge more accurately.
Yards-yd
The length of the football field is measured in yards. Football fields actually use yards to divide the field into sections. Football is a game that uses a lot of math! 10 yards is how far each team needs to go before they can start over again at 1st down. Once you have 4 downs, if you are not 10 yards past where you started 1st down, you turn the ball over to the other team. Distance and math are evident in other sports as well!
Miles-mi
Miles are used for measuring long distances, like the distance across the state. Usually you would use miles when giving driving directions because streets are quite long. Would it make sense to stand on the top of the mountain and say, "I can see for inches"? Probably not. Why do you think this would be awkward to say?
Metric:
Centimeters-cm
Paper clips can be measured in centimeters. Think of a centimeter as the width (the distance across) of your pinky finger. How many centimeters do you think an average paper clip is?
Meters-m
Track and Field uses meters to judge distance. the 100 meter event, is where many runners try and go 100 meters in the fastest amount of time. The 200 is a race of 200 meters, and so on.
Kilometers-km
The distance of the coast is too large to be measured in centimeters, or even meters, so instead you can use kilometers to try and measure the distance of the coast. Kilometers (1000 meters) are used for measuring large distances, as the mile is in American standard units.