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!
Here is another great info chart from www.minnesotacharms.com
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!)
Apron Dress - Measurements & Pattern Sizing by Katla járnkona This form is based upon The Viking Apron-Dress: A New Reconstruction by Ellisif Flakkari (Monica Cellio). Its purpose is to help you 'do the math' for this method.
Sewing, Sewing, Sewing
3" rule for adjusting seam allowances for personalised fit
DIY WITH FABRICS AND NEEDLEWORK
Envelope Expert Site by Crafty Owl. Free online calculator to create any size envelope using the Envelope Punch Board from Stampin' Up!
Envelope Punch Board
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
FREE Woodworking Plans for Sliding Kitchen Cabinet Drawers. Includes a 2-Measurement Calculator for every cabinet size in your kitchen.