what are the proper steps to figuring out what the difference is between 8 1/4 - 5 1/2?

Question

I need to help my daughter figure out easy steps on how to subtract mixed numbers.

Answer 1

ok...well here is a detailed explaination

first you need to conver 8 1/4 to an improper fraction,
in general this means:
a b/c = (a*c +b)/c

in your case
8 1/4 = (8*4 +1)/4 = (32+1)/4 = 33/4

then you need to do the same for the second fraction
5 1/2 = (5*2 +1)/2 = (10+1)/2 = 11/2

now you have the following
33/4 -11/2

well to add this you need to have common denominators (bottoms of the fractions), to do this you need to find the smallest number that both 4 and 2 go into...in this case both of these numbers go into 4...(4*1=4 and 2*2=4)

now you need to get that second fraction to have a denominator of 4...to do this you notice that 2*2 is 4 so we need to multiply that second fraction by 2/2 (so the top and bottom of the fraction is multiplied by 2. you would wonder why the top and bottom...the reason is because 2/2 =1 and we can multiply a number by 1 and it doesnt chage its value...we are just making 1 look funny so we can get the same denomintors

now ...

11/2 * 2/2 = (11*2)/ (2*2) = 22/4 ( we recall we multiply the two top numbers and the two bottom numbers respectively)

now do your subtraction now that we have common denomintaors

33/4-22/4 = (33-22)/4 (here we only subtract the numerator (top))

so 11/4 is our answer

i hope this helps....
matttlocke

Answer 2

Others have this right but here is an easy explanation. you need a common denominator which will be the 4 from the 1/4. The denominator, or bottom of a fraction must match in all numbers to add or subtract the numbers.
what you can do is multipy ANYTHING by 1 and still have the same number so....

8 x (4/4) = 32/4 ...add to the 1/4 and you have 33/4 = 8 1/4
5 x (4/4) = 20/4 ...add (1/2 x 2/2 ) or 2/4 and you have 22/4 = 5 1/2
so 8 1/4 minus 5 1/2 = 33/4 - 22/4 = 11/4
11/4 ( divide it our) = 2 3/4

Answer 3

a million/2 – a million/3 = 3/6 – a million/6 = a million/6 a million/2 – a million/4 = 2/4 – a million/4 = a million/4 a million/2 – a million/5 = 5/10 – 2/10 = 3/10 a million/3 – a million/4 = 4/12 – 3/12 = a million/12 a million/3 – a million/5 = 5/15 – 3/15 = 2/15 a million/4 – a million/5 = 5/20 – 4/20 = a million/20

Answer 4

8 1/4 - 5 1/2
original equation

convert 1/4 to fourths
1/2*2/2=2/4

restate the equation
8 1/4 - 5 2/4

7 5/4 - 5 2/4
take away 1 from 8 and add 4/4 to 1/4

2 3/4
subtract and you'll get your answer

Answer 5

1. Make their bases the same.( 8 1/4 - 5 2/4)
2. Multiply ea. whole no. by its denominator,
(8*4) & (5*4)
3. Add that to the number on top.
4. Simply do (33 - 22) without worrying abt the denominator.
5. Take your answer (11/4) and simplify it. For ea. 4 you subtract from the top (numerator) add 1 to the whole thing.

Answer 6

8 1/4 - 5 1/2 convert 1/2 to fourths
8 1/4- 5 2/4
3-1/4=2 3/4

Answer 7

1/2 is 2/4

so the problem becomes 8 1/4 - 5 2/4

put both of these in their fraction forms 33/4 - 22/4

subtract and convert back to number/fraction

Answer 8

first change both numbers into irrational numbers with the same denominators
33/4 - 22/4

=

11/4

=

2 3/4

Answer 9

The way my dad showed me when I was little was with a ruler. It made much more sense seeing the math in a physical sense.