Question 782884: A woman is 61(1/12) inches tall and her son is 59(1/9) inches tall. How much taller is the woman? Found 2 solutions by edjones, KMST:Answer by edjones(8007) (Show Source):
You can put this solution on YOUR website! 61 1/12 - 59 1/9
=61 3/36 - 59 4/36 (36 is the LCD least common denominator)
=2199/36 - 2128/36 multiply the denominator times the integer + the numerator of each.
=71/36
=1 35/36 inches
.
Ed
You can put this solution on YOUR website! The difference in their heights is
The result is inches of difference in their heights (almost 2 inches).
The mother is inches taller (almost 2 inches taller).
That makes sense because the approximation, calculated dropping the timy and fractions is
61 inches - 59 inches = 2 inches.
When we have to add or subtract fractions, we need a common denominator.
In this case, I would choose, , because it the smallest common multiple of and : } and
THE HARD WAY:
That result can be simplified;
MY WAY:
Sadly, teachers will probably favor the "HARD WAY".
It requires more complicated calculations, and mistakes are more likely, but students can memorize and (at least temporarily) remember a recipe to calculate the result. Understanding why such calculation are done that way; how and why calculations could be done differently, and/or how to estimate the result could be valuable bonuses.