by OneHandKnits

Mathematics and knitting have always gone hand in hand for me, so it was inevitable that I would attempt to encompass a few basic mathematical principles in a blanket for my first offspring. It was an enjoyable challenge both calculating the stitch circumference and relative arcs of the 'pie' slices and then transforming those calculations into a relatively simple knit-engineering solution.

Garter stitch short-rows are used to to form a full 'pie' of rainbow slices and again to 'square the circle'. Varying the relative sizes of each colored slice of 'pie' and changing the orientation of the squares when joining them adds visual interest that belies the simplicity of the actual knit.

Bright colors are ideal for a developing baby's brain.

SIZE
One (to enlarge blanket, see Pattern Notes)

FINISHED MEASUREMENTS
Full blanket: 31.5 x 31.5 inches after blocking
Individual circles: radius of 4.25 inches.
Single squares: 9 x 9 inches.

MATERIALS
Yarn
Sirdar Snuggly Baby Bamboo DK [80% bamboo 20% wool; 105yd/ 96m per 50g skein];
[MC] Mushroom (170); 5 skeins
[CC1] Rocking Horse (126); 1 skein
[CC2] Yummy Yellow (123); 1 skein
[CC3] Orange (166); 1 skein
[CC4] Groovy Green (122); 1 skein
[CC5] Jack-in-a-box (159); 1 skein
[CC6] Baby Berries (161); 1 skein
[CC7] Skittle (127); 1 skein

Recommended needle size
[always use a needle size that gives you the gauge listed below -- every knitter's gauge is unique]
1 set US #6/4mm double-point needles at least 15cm long (3 needed only)
24-32 inch US #6/4mm circular needle
48 inch US #6/4mm circular needle

Notions
yarn needle
5 stitch markers
crochet hook and waste yarn for provisional cast on
4 x 40 inch stiff blocking wires and rust-proof T-pins

GAUGE

PATTERN NOTES
[Knitty's list of standard abbreviations and techniques can be found here.]

This project uses a provisional cast on. Use your preferred provisional cast on technique; directions for one technique may be found here

Instructions for grafting can be found here.

Sl: Slip stitch as if to knit, with yarn at the back.
Slp: Slip stitch as if to purl, with yarn in front.

LLI: Use the left needle to pick up left leg of the purl stitch below the last stitch on the right needle. Knit into the back leg of this stitch. 1 stitch has been increased.

Working the pickup and knit along the edges of the pieces:
When picking up slipped stitches around each circle, use the tip of the LH needle to pick up the right leg of the slipped stitch at the edge, and with the right needle, knit this stitch through the back leg.

Construction:
This is a modular knit with circles worked back-and-forth in short-rows then converted to squares via the short-row working of sts picked-up around the circumference. You can knit all nine circles (note that these consist of five 'A' circles and four 'B' circles) first or work a few circles into squares and join to make a stripe of rotating color pie charts. Joins are worked in St st. The final garter st border requires a long circular needle to encompass the 644 picked up sts that are worked in the round with increasing mitered corners.

Changing the Size:
The original blanket's nine circle-squares can be added to, to make any sized square or rectangle, using the following conventions to calculate additional yarn requirements: Four segments of 'pie' use approx 5g of DK weight yarn. A full circle has 28 segments in total, divided into seven color slices. 'Squaring' three circles and joining them together into a band with two short strips uses 50g of DK weight yarn. Joining three bands of three circle-squares with two long strips and adding a border to the final 3x3 grid uses 100g of DK weight yarn.

You can use the blank schematic to design your own color sequence with the following caveat: each color 'pie' slice has a start row and a finish row in addition to the short-row segments (total of 14 additional straight rows per circle). If you wish to split the segments into less than seven color changes then the extra straight rows should be worked in internally to one or more 'pie' segments to balance out. Changing color more than seven times is not advised as this will add too many extra rows and distort your circle.

DIRECTIONS
Circle A (make five)
With yarn CC1 on 2 US #6 dpns, CO 20 sts using a provisional cast on (see Pattern Notes for details).

Row 1 [WS]: K19, p1.

Row 2 [RS]: Sl1, k14, LLI, turn.

Rows 3, 5, & 7 [WS]: Slp 1, k to last st, p1.

Row 4 [RS]: Sl1, k9, LLI, turn.

Row 6 [RS]: Sl1, k4, LLI, turn.

Row 8 [RS]: Sl1, k4, [k2tog, k4] 3 times, LLI. Place inc st onto 3rd dpn and hold to one side.

Row 9 [WS]: K19, p1.

Change to CC2.
Next row [RS]: Sl1, k to end.

Work rows 1-8 twice, then Row 9 once.
Note: Place the sts created at the end of each Row 8 onto 3rd dpn to the right of the st(s) already there.

Change to CC3.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 3 times, then Row 9 once.

Change to CC4.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 4 times, then Row 9 once.

Change to CC5.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 5 times, then Row 9 once.

Change to CC6.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 6 times, then Row 9 once.

Change to CC7.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 7 times.

Slip each st from the 3rd dpn off in turn over the last inc st added (27 st are bound off in this way in total) pulling your piece into a circle. With the yarn held in front slp the rem inc st back onto the RH needle. Turn to the WS, k2tog, k to last st, p1.

Cut a 12 inch yarn tail. Carefully return remaining provisional CO sts to a needle. Use the yarn tail to graft the two sides together. Weave the rem yarn through the center loops to bury it.

Change to CC2.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 6 times, then Row 9 once.

Change to CC3.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 5 times, then Row 9 once.

Change to CC4.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 4 times, then Row 9 once.

Change to CC5.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 3 times, then Row 9 once.

Change to CC6.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 twice, then Row 9 once.

Change to CC7.
Next row [RS]: Sl1, k to end.
Work Rows 1-8 once.

Slip each st from the 3rd dpn off in turn over the last inc st added (27st are bound off in this way in total) pulling your piece into a circle. With the yarn held in front slp the rem inc st back onto the RH needle. Turn to the WS, k2tog, k to last st, p1.

Cut a 12-inch yarn tail. Carefully return remaining provisional CO sts to a needle. Use the yarn tail to graft the two sides together. Weave the rem yarn through the center loops to bury it.

Squaring each circle
There will be 120 slipped sts around the edge of the circle (give or take one or two). You'll be working in quarters -- 30 slipped sts at a time.

Beg at the grafted join, using US #6 shorter circular needle, place the right leg of the first slipped sts onto the LH needle so that it sits as regular st would. Join yarn MC and ktbl. Rep for the next 29 slipped sts (to cover a quarter of the circumference of your circle). 30 sts total. Turn to the WS.

You should now have 23st (incl lifted inc st) to the right of the marker and 22st to the left of the marker. **Pick up and ktbl each of the next 30 slipped sts as described above (the next quarter of the circumference of your circle). Turn to the WS. Rep Rows 1-16. Rep from ** twice more to completely enclose the circle. 180 sts.

Join for working in the round, placing a marker for start of round.

Round 1: Purl around.
BO as follows: [BO to 1 st before marker, m1, pass previous st over incr, k1, pass incr over knit st to BO, remove marker, m1, pass previous st over incr st] four times, BO as normal to the end of the round. Pull yarn through last rem st.

Joining squares into bands:
On the shorter set of US #6 circular needles in MC and using the schematic to orient your squares, pick up 49 loops along one BO edge of a square, knitting each in turn tbl. Work back and forth in St st for 10 rows starting with a WS purl row.

With RS facing together, use US #6 dpn to pick up a loop from the appropriate BO edge of the next square (oriented according to schematic), starting at the right hand corner. Work this 'st' with the 1st st of the St st strip as a p2tog. Rep pick up and p2tog with the next sts from the BO edge and St st strip. On RH needle, pass 1st st over 2nd st to BO. Cont to work in this manner until all sts from the St st strip are joined to the next square and bound off. Pull yarn through the last rem st.

On the opposite edge of the 2nd square, pick up 49 loops from the BO, joining yarn MC and knitting each in turn tbl. Rep strip and join instructions as above to add a 3rd square to the band.

Joining bands:
On the longer set of US #6 circular needles in MC and using the schematic to orient your bands, pick up 161 loops along the long top edge of a band (49 loops along the BO edge of each square, 5 slipped st across each strip and 1st in each square-strip join) knitting each in turn tbl. Work back and forth in St st for 10 rows starting with a WS purl row.

With RS facing together, use US #6 dpn to pick up a loop from the bottom edge of the next band (oriented according to schematic), starting at the right hand corner. Work this 'st' with the 1st st of the St st strip as a p2tog. Rep pick up and p2tog with the next sts from the BO edge and St st strip. On RH needle, pass 1st st over 2nd st to BO. Cont to work in this manner until all sts from the St st band are joined to the next band and bound off. Pull yarn through the last rem st.

On the opposite long edge of the 2nd band, pick up 161 loops, joining yarn MC and knitting each in turn tbl. Rep strip and join instructions as above to add a 3rd band to the grid.

Join for working in the round, placing a distinct marker for start of round.

Round 1: Purl around.
Round 2: [M1, k to 1 st before marker, m1, k1, slip marker] four times. 8 sts increased.

Rep Rounds 1-2 3 times more, and Round 1 again (676 sts)
BO as follows: [M1, k1, pass incr st over knit st to BO, cont to k1 and pass prev st over to 1 st before marker, m1, pass previous st over incr to BO, k1, pass incr st over to BO, drop marker] four times.

FINISHING
Wet block to dimensions given. Weave in ends.

OneHandKnits is the design brand of Anna Richardson, a former doctor turned hedonistic knitwear designer trying to square running a business within the circle of sustainable living. This mostly seems to involve a 'do-it-yourself' attitude to life that underpins her love of designing and making. Also a lot of camping. She can usually be found extolling the virtues of live local music in inner SE London where she grows veg and keeps fancy rats. She will be giving birth for the first time in March 2013.

More OneHandKnits patterns can be found here.