I don't know that I would call it 'double symmetry' or 'repeating radial' as
much as I would just identify different lines of symmetry/reflection. Some
shapes/designs may have one line of symmetry/reflection, 2 and so on. The
use of mirrors (or the math tool, Mira) help to find those lines.
The directions were for needlework, the stripes were worked in half stitches
vertically skipping stitches, when the same pattern was overlapped
horizontally, everything was filled in. If you have lots of fabric swatches
for the kids to look at, they will see what happens with a plaid.
The plaid consists of a pattern that is repeated vertically and
horizontally. There is some flexibility with the pattern and the date.
There isn t only one right way to complete this, so you may just want to use
these directions for a starting point.
If you are doing the birthday December 12, 1958, your beginning set of
stripes my look like this:
12 rows of blue, 12 rows of yellow, 5 rows of green and 8 rows of orange. I
would consider this a unit. You could reflect the pattern over a line of
symmetry, so that it could look like this:
12 B, 12 Y, 5 G, 8 O (1 row of a color for line of symmetry)8O, 5 G, 12 Y,
After completing this ?reflected unit with vertical rows, you my want to
skip (you don t have to leave it blank - just pick a ?background color) and
have several open areas. (Something like 10 or 12.) Repeat the pattern
Turn the paper 90 degrees and continue with the pattern (or just leave the
paper and repeat the pattern horizontally.)
Flexibility comes with dates like January 29, 1918. The numbers would be
22.214.171.124. The 29 could be regrouped into 2 rows plus 9. (That represents 2
tens and 9 ones.) Again that is up to the designer.
I was going to try it with translucent markers so that overlapping rows would
be darker, or strips of tissue paper. If you use graph paper, you may want
to try the small squares (scientific?), or use the 1/4 grid and have the
students color in half triangles. Overlapping the horizontal and vertical
would complete the squares. If you were weaving with paper, the ?numbers
could be strips of paper cut into centimeters (12 cm, 12 cm, 5 cm, 8cm for
the first example...) so many possibilities...
If anyone is interested - there is another way to use special days in a
design. There is a quilting book called ?Crystal Piecing by Barbara Johanna
(pronounced Yohanna) that describes a process developed by Jane (Jan?)
Texas. It is based on Douat s Infinite Design System. It is a wonderful
lesson for math too. Lots of geometry... reflections, rotations, and
translations (Flips, turns and slides. ) The math starts with calculating
the possible number of outcomes for a series of black, white triangles. We
did ours with stamps made from pencil erasers cut into triangles (this fit on
1/4 inch grid paper), then we used triangle stamps cut out of 1 gum erasers,
we used 1 graph paper as a guide under colored tissue paper, and stamped our
birthdays. The tissue paper can be sewn into a quilt. (Sewn into a patchwork
piece? I guess it could be quilted...)
I hope I haven t confused anyone... if I could only draw it for you!