As the second equation is equivalent if you divide the entire equation by 2

Math assignment = 3/8 hours

History assignment = 1/4 hours

We can not compare this as both fractions do not have alike denominators.

We can fix this problem easily by turning 3/8 and 1/4 into alike denominator fractions.

We can turn 1/4 into 2/8 as it is equivalent fractions.

1 x 2 = 2

4 x 2 = 8

(Whatever you do to the denominator, you have to do the same to the numerator)

Once we get this, we can see that Shen spent 2/8 hours on his homework while he spent 3/8 hours on his math assignment.

3/8 - 2/8 = 1/8

1/8 = 0.125

Shen spent 1/8 of an hour (or 0.125 of an hour) more on his math assignment than his history assignment.

**Answer:**

81

**Step-by-step explanation:**

To do "how many times greater" problems, you divide. Think how you would answer this: How many times greater is 48 than 6? Dividing the larger 48 by the smaller 6 gives 8. 48 is 8 times greater than 6.

Do the same thing for these two masses.

6 x 10^24 divided by 7.4 x 10^22 is about 81.

The attached image shows a TI-83 display.