Problem 1
height of flagpole = meters (SI), feet (imperial)
area of walls = square meters (SI), square feet (imperial)
amount of water = liters (SI), gallons (imperial)
volume of grocery bag = liters (SI), gallons (imperial)
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There's not much explanation here. It's simply something you memorize.
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Problem 2
1 ft = 12 inches
5 ft = 60 inches .... multiply both sides by 5
5 ft, 10 in = 60+10 = 70 inches
To convert from inches to cm, we multiply by 2.54 (approx)
70 in = 70*2.54 = 177.8
Shane is roughly 178 cm tall
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Problem 3
1 km = 1000 m
0.65 km = 650 m .... multiply both sides by 0.65
1 m = 100 cm
650 m = 65000 cm ... multiply both sides by 650
We can see that 0.65 km is the same as 65000 cm
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Problem 4
1 pound = 16 ounces
Based on this, we divide by 16 to go from ounces to pounds
50 oz = 50/16 = 3.125 pounds