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Annie ran 5/8 of a mile. Lexi ran 7/10 of a mile who ran further?

User Jmbucknall
by
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1 Answer

4 votes

Explanation:

so, the question is

5/8 > 7/10 ?

or

7/10 > 5/8 ?

to compare fractions for real we need to bring them both to the same denominator (bottom part). then the numerators (top part) can give us all the answers precisely.

to bring a fraction to another denominator we can either split it further into subunits (like splitting halves into quarters, or 1/2 = 2/4), combine subunits (simplify the fraction) like from 2/4 to 1/2.

now, what number would designate subunits for tenths and for eighths ?

the easiest way (works always) is simply to multiply both numbers : 10×8 = 80. so, we are looking at x/80.

but we can simplify this by finding the least common multiple (LCM) of both numbers.

that is actually 40 for 10 and 8.

40 = 4×10 = 5×8

so,

5/8 = (5×5)/40 = 25/40

7/10 = (7×4)/40 = 28/40

that means

7/10 > 5/8

and Lexi ran therefore further.

User Tauheedah
by
8.5k points

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