Unit ConversionsDate: 11/16/95 at 11:44:15 From: L. Johnson Subject: Math question How many centimeters are in 1,200,345 yards? Karen Goings Date: 11/19/95 at 15:32:8 From: Doctor Jeremy Subject: Re: Math question Here's a technique to figure out almost any such unit-conversion problem, using fractions. You treat the units (yard, foot, cm) as if they represented some numbers, the actual values of which you don't know. You can find out (by looking it up in an appropriate book like an almanac) that there are 3 feet in a yard. So you make a fraction 3 feet ------ yard Since "3 feet" and "1 yard" are the same, the whole fraction is equal to 1. You also know that there are 30 centimeters (approximately) in a foot. This gets you 30 cm ----- foot Now since both of these fractions are just equal to 1, multiplying a value by them does not change that value. So 1,200,345 yards 3 feet 30 cm 1,200,345 yards = --------------- x ------ x ----- 1 yard foot 1,200,345 * 3 * 30 * yard * foot * cm = ------------------------------------- yard * foot And cancelling the extra yard and foot, and doing the multiplication, you get 108,031,050 cm You can do this with almost any sort of units; in physics and chemistry classes it comes in very handy. -Doctor Jeremy, The Geometry Forum |
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