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HELP! I need a mathematician quickly!

HELP! I need a mathematician quickly!

Old 08-11-2013, 08:15 AM
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Unhappy HELP! I need a mathematician quickly!

Before I start cutting I need to know if I have enough fabric and for the life of me I can't figure it out without out coming up with a half dozen different figures. I have 63 - 9 1/2" unfinished blocks - of course 9" finished. I want to sew them 9 rows down by 7 rows across and want to put 1" finished (cutting 1 1/2) sashing. I plan on sewing strips on one side of each block, sewing the rows together and then joining rows with long strips.

PLEASE tell me how much yardage (42" width) I need. I can't imagine why I didn't post this yesterday....I know I could have saved myself MUCH time and stress and probably could have it done by now...LOL.

Thanks for any help I may be given. Pat
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Old 08-11-2013, 08:49 AM
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So, you want 8- 9.5" strips 1.5" wide for each row, multiply by 9 rows = 72 9.5" strips 1.5" wide

You can get 4 of these trips from one WOF, so you need 72/4 or 18 1.5" strips = 24", or 2/3 yard, round to 3/4 yd.

And you need 10 strips of the 7 9" finished blocks with 1" sashing + 1.5" = 10 strips of 71.5" = 715" of 1.5" strip.

You can make one strip from 2 WOF or piece them further.

To use 2 WOF for one strip means that you need 10 strips 3" wide = 5/6 yard, round to 1 yard

or with more piecing:
715" / 40" WOF = 18 1.5" strips = 240" length of fabric /36" per yard = 2/3 yd, round to 3/4 yd

So, 3/4 yd + 3/4 yd would be minimally sufficient = 1.5 yd, but I would round to 1.75 or 2 yards to have enough to cover cutting errors or unsquared fabric.

Sue
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Old 08-11-2013, 08:59 AM
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Well, assuming your blocks are all cut square of the same fabric at 9.5 inches, and not pieced from different fabrics, out of one yard of fabric (42" x 36") you will only get 9 9.5 inch blocks. For 9 across and 7 down you will need 63 blocks, which means 7 yards of fabric just for the blocks. However, if you are piecing fabric to come up with your 9.5 inch block you would need to figure out each fabric separately. For the sashing you will need approximately 1,100 inches. At 1 1/5 inches wide per sashing strip you could conceivably get 24 strips out of a yard, which would give you 1008 inches. So for the sashing you should be absolutely safe with 1 1/4 yards of fabric. Good luck
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Old 08-11-2013, 09:05 AM
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Originally Posted by charsuewilson View Post
So, you want 8- 9.5" strips 1.5" wide for each row, multiply by 9 rows = 72 9.5" strips 1.5" wide

You can get 4 of these trips from one WOF, so you need 72/4 or 18 1.5" strips = 24", or 2/3 yard, round to 3/4 yd.

And you need 10 strips of the 7 9" finished blocks with 1" sashing + 1.5" = 10 strips of 71.5" = 715" of 1.5" strip.

You can make one strip from 2 WOF or piece them further.

To use 2 WOF for one strip means that you need 10 strips 3" wide = 5/6 yard, round to 1 yard

or with more piecing:
715" / 40" WOF = 18 1.5" strips = 240" length of fabric /36" per yard = 2/3 yd, round to 3/4 yd

So, 3/4 yd + 3/4 yd would be minimally sufficient = 1.5 yd, but I would round to 1.75 or 2 yards to have enough to cover cutting errors or unsquared fabric.

Sue
Ironically I have 1 3/4 yards of fabric that I want to use.....I guess I'll chance it...LOL. I still don't understand the calculations....just going by the bottom number. And believe it or not I was a bookkeeper in my younger years and loved solving this kind of problem. I've lost it along the way.

Thank you so much. I knew I'd find someone capable on here.
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Old 08-11-2013, 11:17 AM
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Originally Posted by davis2se View Post
Well, assuming your blocks are all cut square of the same fabric at 9.5 inches, and not pieced from different fabrics, out of one yard of fabric (42" x 36") you will only get 9 9.5 inch blocks. For 9 across and 7 down you will need 63 blocks, which means 7 yards of fabric just for the blocks. However, if you are piecing fabric to come up with your 9.5 inch block you would need to figure out each fabric separately. For the sashing you will need approximately 1,100 inches. At 1 1/5 inches wide per sashing strip you could conceivably get 24 strips out of a yard, which would give you 1008 inches. So for the sashing you should be absolutely safe with 1 1/4 yards of fabric. Good luck
Thank you also, Davis. You made me feel good - I already have my 63 blocks made and you made me realize how much money I saved making them all from strips of scrap. Even the 1 3/4 yards that I have and want to use for sashing is scrap fabric. I LOVE Scrappy Quilts...as much as I love saving money...LOL.
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Old 08-11-2013, 11:51 AM
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Originally Posted by PghPat View Post
Ironically I have 1 3/4 yards of fabric that I want to use.....I guess I'll chance it...LOL. I still don't understand the calculations....just going by the bottom number. And believe it or not I was a bookkeeper in my younger years and loved solving this kind of problem. I've lost it along the way.

Thank you so much. I knew I'd find someone capable on here.
I have a Master's Degree in Business with 18 additional graduate level hours in Accounting. I teach accounting on the college level but I too am struggling with quilter's math! It's just intimidating the heck out of me!! i am so thankful for the good folks on this board to help me out. One of these that light bulb will go off over my head and I will understand it!!
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Old 08-11-2013, 12:20 PM
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Looks like you already have your squares cut -

But if you wanted to cut all of them from one piece of fabric:

The way I figured this:

Assumptions:
(1)You are not fussy cutting? Fussy cutting is cutting so only certain parts of a pattern/stripe/design is showing - it usually takes more fabric than 'just cutting'
(2) You are cutting all the blocks from one fabric

The basic steps are:

1) How many squares can one get from a width of fabric?
(divide width of fabric by size of square - round down to the whole number)
2) How many widths of fabric will one need?
(divide total number of squares by number of squares from one width - round up to next whole number)

I can get four 9.5 inch squares out of a width of 42 inch fabric. (9.5 x 4 = 37 inches)

63 divided by 4 = 15.75 (one needs to round up to the next higher whole number)

It will take 16 widths of fabric to cut 63 squares (one left over from the last row)

16 rows x 9.5 inches = 152 inches

152 inches divided by 36 inches = 4.222 yards

Last edited by bearisgray; 08-11-2013 at 12:24 PM.
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