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Subtracting Mixed numbers

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rowdy3
Advanced Member

USA
57 Posts

Posted - 09/24/2007 : 09:12:51

Toni and Mandy purchased a roll of wallpaper from the craft shop that unrolls to 32 1/4 yd. Sue will use 27 5/8 yd of the roll to wallpaper Mandy's bathroom and 4 1/4 yd to wallpaper Toni's bathroom. How much wallpaper will be left over?

I added 27 5/8 and 4 1/4. I got 32.08 and I subtracted 32.08 from 32.25. I got .17. How do I put that into a fraction. I tried 17/100 but it's wrong.

Subhotosh Khan
Advanced Member

USA
9114 Posts

Posted - 09/24/2007 : 11:59:48

quote:
Originally posted by rowdy3

Toni and Mandy purchased a roll of wallpaper from the craft shop that unrolls to 32 1/4 yd. Sue will use 27 5/8 yd of the roll to wallpaper Mandy's bathroom and 4 1/4 yd to wallpaper Toni's bathroom. How much wallpaper will be left over?

I added 27 5/8 and 4 1/4. I got 32.08(this is incorrect - however follow David's advice of not converting to decimals) and I subtracted 32.08 from 32.25. I got .17. How do I put that into a fraction. I tried 17/100 but it's wrong.

rowdy3
Advanced Member

USA
57 Posts

Posted - 09/24/2007 : 13:07:35

i added the numbers inside the parenthesis and got 31 7/8. I subtracted and got 1 5/8. Is that correct?

skeeter
Advanced Member

USA
5634 Posts

Posted - 09/24/2007 : 13:16:14

yes ... (27 + 5/8) + (4 + 1/4) = 31 + 7/8

however ... (32 + 1/4) - (31 + 7/8) does not equal 1 + 5/8

try changing 32 + 1/4 to 31 + 5/4 ... now subtract and see what you get.

rowdy3
Advanced Member

USA
57 Posts

Posted - 09/24/2007 : 15:54:12

would it be 1 3/8

skeeter
Advanced Member

USA
5634 Posts

Posted - 09/24/2007 : 21:57:13

no ...

(31 + 5/4) - (31 + 7/8) =

(31 + 10/8) - (31 + 7/8) = 3/8

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