I had no idea there was such a cool tool online for building stairs! For someone who sucks at math in a big way, this is nothing short of a dang miracle!!
hexagon calculator - this is for sewing but would work with crochet as well!
Hooked on Crochet
A chart for piecing standard width fabrics for comforters to avoid a center seam. This is great so I don't have to calculate it myself any more!
Circle skirt calculator – for the drafting of full, half and 3/4 skirts. With bonus grading worksheet! (I'm sure if I ever learn to sew, this will be super-handy!)
Here is another great info chart from www.minnesotacharms.com
3" rule for adjusting seam allowances for personalised fit
DIY WITH FABRICS AND NEEDLEWORK
FREE Woodworking Plans for Sliding Kitchen Cabinet Drawers. Includes a 2-Measurement Calculator for every cabinet size in your kitchen.
Math - Metric conversion trick using "King Henry Died Unusually Drinking Chocolate Milk." This simplifies the whole metric conversion process and makes it fun! Includes a very nice freebie for grade 6
Tips for determining quilt size if you want to exactly fit different mattress widths. Comforter, Coverlet and Bedspread plus standard sizes for all bed types (follow the link on the first page of the post)
Enter your height and waist measurement & it calculates all the correct measurements to make a kimono