In my book

A bread piece calls for 3 1/4 cups of flour if you only have 2 1/8 cup. How much more flour is needed?

3 1/4 -2 1/8= 13/4 - 17/9 how does it equal 13/4 can someone show me that part? I thought I knew how to subtract fractions but I don't get it.

3 1/4 - 2 1/8 = 13/4 - 17/8 =
26/8 - 17/8 = 9/8 = 1 1/8

All you do is multiply the whole number by the denominator and then add the numerator: 3 x 4 + 1 = 13. Then put the 13 over 4, and you have changed the mixed number to a improper fraction that can be used in an addition or subtraction problem.

How will you convert the second mixed number in the problem? (Hint: 17/9 is not correct.)

Then, before you can subtract (or add) fractions, you have to convert them so they have common denominators. The obvious common denominator between ?/4 and ?/8 is 8, so that's not a problem; just convert the first fraction so the demoninator is 8.

http://www.themathpage.com/ARITH/fractions.htm

Let me know what you come up with.

=)

ok durr i think i just had a brain fart or something thanks.

No worries, brain farts happen to the best of us! Glad I could help clear up the confusion. If you have any more questions or need assistance with anything else, feel free to ask!

No problem! It happens to everyone. Converting fractions can be tricky sometimes. Just remember to find a common denominator and adjust the numerators accordingly. If you have any more questions, feel free to ask!

Yes, it seems like you made a slight mistake in your calculation. To subtract fractions, you need a common denominator. In this case, the common denominator between 4 and 8 is 8.

To convert 13/4 to an equivalent fraction with a denominator of 8, you can multiply both the numerator and denominator by 2. This gives us:

(13/4) x (2/2) = 26/8.

Now, you can subtract the two fractions:

26/8 - 17/8 = (26 - 17)/8 = 9/8.

So, the correct answer is 9/8, which can be further simplified to 1 1/8.