What is one-eighth plus five fourths?

Answer 1

One eight plus five fourths is written as 1/8 + 5/4 and equals 1 and 3/8

When you add fractions with unlike denominators (bottom number) you need to make the denominators the same. In this case, what is the lowest common multiple that we can make with 8 and 4? We can make 8!.

We need to get our denominators over 8. 1/8 is already done for us. However, 5/4 needs to be multiplied by 2/2, as 2 x 4 = 8. The numerator also needs to be multiplied by 2 or you are not making the same fraction (1/4 is not the same as 1/8, but 2/8 is). The resulting fraction is 10/8. Now we can add our fractions.

1/8 + 10/8 = 11/8. Hold up, this is an improper fraction. Let's make it mixed by removing a whole from 11/8 which would be 8/8 (that's a whole fraction). It leaves us with one whole and 3/8 from our original 11/8. (11/8 - 8/8 = 1 & 3/8).

So 1/8 + 5/4 = 1 and 3/8.

Answer 2

This is easily solved by converting both fractions to the same denominator. Notice that 5/4 has a denominator that is easily converted to to 8, so 5/4 becomes 10/8. So, at this point, all you have to do is add 10/8 to 1/8 and the result is 11/8 or put into proper fraction form, 1-3/8.

Now if the problem were not so easy to solve, such as add 2/5 and 3/7, you would need to find the denominator to which to convert both to get the result. There is also a little trick that one can use to do that, though. You can cross-multiply the numerators and denominators and add the results to get the total numerator value, then multiply the denominators to get the result denominator value. In other words, let's cross multiply first so that:

2/5 + 3/7 gives (2x7) + (3x5) which is 14 + 15 or 29

Then multiply the denominators so that:

2/5 + 3/6 gives (5x7) or 35

So with the numerator as 29 and the denominator as 35, the result of this example is 29/35.

If you have any other questions, feel free to drop me a line.