SLEEVE INCREASES EXAMPLE #1:
If you want to shape a sleeve and evenly distribute increases
across all rows you would divide stitches by rows. For instance, the
bottom of the sleeve has 20 stitches and the top has 90 stitches. That
means that you would have 70 stitches to increase evenly across all
rows. You get to this number by subtracting the sleeve cuff stitches (20) from the top of the sleeve stitches (90) and you have 70 stitches remaining.
No need to use the Magic Formula
90 stitches - 20 stitches = 70 stitches for increasing
BUT, you need to half this number as with a sleeve you increase on BOTH
sides, otherwise you will get a lopsided sleeve. So, now you have 35
70 stitches divided by 2 (sides) = 35 stitches
Also, in this example, you know that you have 140 rows to knit the sleeve
increases, you know this by your swatch for yarn gauge, the arm measurement or the pattern. So, you
take your rows of 140 and divide "BY" 35 stitches (35 each side is 70) and
you get the number 4. Which is lucky because 140 is divisible by 35.
140 rows divided by 35 stitches = 4
This means you will add a stitch on each side on every 4th row until you reach 90 stitches, or 35 times. Simple enough!
But what happens when you divide rows and stitches but cannot get a
whole number? What do you do with the leftover? That is where the
Magic Formula comes in.
With the next example, #2, you need to look at it like a stack of
building blocks. One calculation builds off of another one. I have
also color coded some of the numbers so it is easier to follow along.
SLEEVE INCREASES EXAMPLE #2:
What was most confusing for me is the use of the number one (1). I
also had to change my thinking on how to divide. Example #1, I was
dividing "BY" Rows "BY" stitches. With this example, #2, you will be
dividing "INTO" Stitches "INTO" rows.
I will try my best to describe this equation using the Magic Formula...
Let's say you have a sleeve and you have 25 stitches at the cuff and 121
stitches at the shoulder sleeve area. You take 25 from 121 to find out
how many stitches you need to increase, which is 96 stitches.
Using the Magic Formula
121 stitches - 25 stitches = 96 stitches to increase
Then you divide 96 by 2 because you increase 1 stitch on each side (I
always forget to half the stitches). So now you have 48 stitches.
96 stitches divided by 2 (sides) = 48 stitches or increase 48 times
Increase 1 stitch on each side 48 times
You know from your test swatch that you have 136 rows to use for increases. So, you take 136 and divide "BY" 48 and you get 2.833. I always check to see if I come out with a whole number, or a number that it is divisible by, because then you do not need to use the Magic Formula.
136 rows divided by 48 stitches = 2.833
Uh Oh, now what?
Since you have a remainder of ".833" you know that you now have to switch
your thinking and start using the Magic Formula in order to increase
evenly across all rows.
NOTE: First, I am assuming that you are NOT counting the cuff ribbing, if that
is what you have done for the edge of the cuff. I also am assuming you are not counting any rows that you
may want to knit at the beginning of the sleeve. I sometimes crochet
cast-on 3 or 4 rows when I do not use ribbing and then knit 2 rows for
the cuff for a nice edge. I also am assuming that the increase is for a
Drop Shoulder sleeve, and not a set in sleeve, with say, 5 rows of
plain knitting with no changes before I cast off.
So, you take 136 rows and divide 48 stitches "INTO" 136, NOT DIVIDE BY, you are asking yourself HOW MANY TIMES CAN 48 GO INTO 136.
48 stitches can go INTO 136 rows 2 times (48 + 48 = 96)
....with 40 stitches left over
We then subtract the remaining stitches (40) from the actual stitches required which is 48 minus 40 is 8.
48 - 40 = 8 stitches
Then add 1 (one) to the number of of how many times the 48 stitches can go into the rows, which is 2, so 2 plus 1 is 3.
You then state that you:
-Increase 1 stitch at each side at the end of every 2nd row 8 times
- Increase 1 stitch each side at the end of every 3rd row 40 times
To double check your work...
ROWS should be 136:
2 rows @ 8 times = 16 rows
3 rows @ 40 times = 120 rows
TOTAL 136 ROWS
STITCHES should be 96 :
**2 stitches because you increase 1 each side, so you count 2
2 stitches @ 8 times = 16 stitches
2 stitches @ 40 times = 80 stitches
TOTAL 96 STITCHES
Do not ask me how this works out every time,
but it does. You just need to remember the steps, which numbers go
where and in which order. In other words, there is a "direct relationship" with certain numbers and it always works the same way.