Ask a question

what is 6 1/2*3 1/4

Please help me I dont know how to do this or figure this out PLEASE help me

2 Answers by Expert Tutors

Tutors, sign in to answer this question.
Vivian L. | Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACHMicrosoft Word/Excel/Outlook, essay comp...
3.0 3.0 (1 lesson ratings) (1)
Hi Eliana;
6 1/2*3 1/4
Let's convert each number into fractions...
6 1/2=13/2
The numerator, number on top, is equal to [(6)(2)]+1=13
The denominator, number on bottom remains unchanged.
3 1/4=13/4
We will now multiply the numerators together, (13)(13)=169
We will now multiply the denominators together, (2)(4)=8
We can convert this into a whole number and a fraction.
169 divided by 8=21 and a remainder of 1.
21 1/8
Catherine F. | Catherine F. Math, Science, Biology, AnatomyCatherine F. Math, Science, Biology, Ana...
4.3 4.3 (3 lesson ratings) (3)
In order to answer this problem you need to first convert both of the mixed numbers into improper fractions.
To convert to improper fractions, you multiply the whole number by the denominator, then add that to the numerator. Then you write that number above the denominator you started with.  So..
6 1/2  would become 13/2
(6×2=12 ---> 12+1=13)
3 1/4 would become 13/4
(3×4=12 ---> 12+1=13)
So now you have 13/2 × 13/4
Now you multiply across (numerator × numerator and then denominator × denominator)
13×13= 168   and 2×4= 8
So now you have 168/8.
Then to convert back to a mixed number you divide the numerator by the denominator.  In this case 168÷8 = 21 so you are left with just a whole number because there is no remainder.  You could also look at it as:
21 0/8  (but this is really not necessary.  When you DO have a reminder,  then that number would go over the denominator to make a mixed number)
So the answer is 21.