Speed of Everything in MPH for Multiple Hours

After studying the speed of light and sound last week, we built on that knowledge by looking at the speed of 30 different objects, natural phenomenon, animals, people, and even a cliche. We even debunked a few myths such as the speed of the human sneeze is 100 miles per hour; it is only about 25 MPH. We also looked at the running speed of the average human. See the pdf called Speed of Everything in MPH with Explanations.

With the 3-5th graders, we converted the speed of light in miles per second to miles per hour by multiplying by 60 and then 60 again (x3600) and converted the speed of sound in feet per second to miles per hour by doing the same x3600 but then dividing by 5,280 (feet per mile); many chlldren wanted to multiply by 5,280 so we focused on the importance of understanding the correct uses of operations.

We then focused on how far in miles an object would travel at their MPH speed for multiple hours. With the K class we focused only on multiplying by 10 hours, essentially tacking on a zero (not adding a zero) onto the number moving the place value. This reinforced their skills in writing down numbers and reciting the place value of numbers. With the 1st graders we introduced multiplying by 5 by dividing the x10 by two; cutting the number in half. We focused on breaking up the number into its manageble parts and cutting each part in half and then adding those halves together. For example, when halving 610. First take half of 600 which is 300 then taking half of 10 which is 5; then add 300 to 5 to get 305.

With the 2nd-3rd graders we focused on multiplying by 15 by simply adding the result from x10 and x5. To multiply by 30, they recognized they could just double the x15 result. With the older groups we also looked at multiplying by powers of 2 (2,4,8,16,etc,) by doubling multiple times. I call this the turkey method (double, double, double for multiplying by 8).

Try the following three pdfs to find out how far these 30 objects travel in 10, 5, 15, 30, 2, and 4 hours.

I also challenged the children to do research on speed to correct any mistakes I made on the spreadsheet. There was some debate about the fastest car, a cheetah, etc.