Measurement and EstimationLength / Distance

MCOM 520

Ryan Connors

History of Measurement

• What is measurement?

The English System of Measurement – Length/Distance

• How do we measure length and distance in the English System?

– Inch, Foot, Yard, Mile

• There are 3 feet in a yard, and 5,280 feet in a mile. How many yards are in a mile?

– The answer is 5,280/3 = 1,760 yards

• If a football field is 100 yards and there are 1,760 yards in a mile, how many football fields are in a mile?

– The answer is 1,760/100 = 17.6 football fields

The Metric System of Measurement – Length/Distance

• Who uses this form of measurement?

• What are some examples of units of distance in the Metric System?

• Units of measure in the Metric System are based on one unit of measure

– Length is based on the meter• The meter is around 3 feet

Metric System - Length• Millimeter – “milli” means Thousandth

– So a millimeter is actually 1 meter/1000.

• Centimeter – “centi” means Hundredth – So, a centimeter is actually 1 meter/100.

• Decimeter – “deci” means Tenth – So, a decimeter is actually 1 meter/10

• Decameter – “deca” means Ten – So a decameter is actually 1 meter X 10

• Hectometer – “hecto” means One Hundred – So, a hectometer is actually 1 meter X 100

• Kilometer - “kilo” means One Thousand– So a kilometer is actually 1 meter X 1000

http://school.discoveryeducation.com/clipart/clip/thinkingcapwhoa_color.html

Metric System - Length• How many millimeters are in a kilometer?

– There are 1,000 millimeters in a meter, and a kilometer is 1,000 meters. So, the answer is 1000 X 1000 = 1,000,000 millimeters

• How many centimeters are in a kilometer?

– There are 100 centimeters in a meter, and a kilometer is 1,000 meters. So the answer is 100 X 1000 = 100,000 centimeters

Metric Measurement• How wide is the tennis ball in

centimeters?

• The answer – the left side of the ball appears to start at 50 centimeters. The right side of the ball seems to end at 57 centimeters. 57-50 = 7 centimeters!

• Bonus question: Can you figure out how many tennis balls would equal a meter?

http://www.phys.selu.edu/rhett/plab194/tennis-1.jpg

Estimation

• What is estimation?– Educated guess – Webster’s dictionary describes an

educated guess as “a guess based on knowledge and experience, making it more likely to be correct”

Keyboard Estimation Exercise

• Take out your paper rulers!

– Which side is centimeters?

– Which side is inches?

Keyboard Estimation Exercise

• Measure the first three keys on the top left hand corner of the main section of keys on your keyboards. (~, 1, 2) in centimeters and inches.

• Enter the values into the corresponding columns on your worksheets

Keyboard Estimation Exercise

• Can you estimate the length of your keyboards?

– Enter the estimated total length of your keyboards in the corresponding columns on your worksheets

Summary

• The English system of length measurement uses the inch, foot, yard and mile.

• The Metric system of length is based on the meter. It uses the millimeter, centimeter, decimeter, decameter, hectometer, and the kilometer.

• We can use estimation to gain knowledge about the size of objects when we have limited resources to measure

• Please complete the worksheet for the remainder of the class!

Citations• Scientific Method and Measurement. United Learning

(1993). Retrieved March 4, 2008, from unitedstreaming:

http://streaming.discoveryeducation.com • Discovering Math: Measurement (Grades 3-5). Discovery Channel School

(2005). Retrieved March 4, 2008, from unitedstreaming:

http://streaming.discoveryeducation.com/ • Worm on ruler image: http://school.discoveryeducation.com/clipart/clip/inchworm.html