Operator Reference
Pie Wheels
Twelve formulas rearrange often enough to be worth memorizing as a picture. Cover the piece you want and the wheel shows you the arithmetic.
How to read a wheel
- Multiply the wedges underneath the line to get the quantity on top.
- Need one of the bottom wedges instead? Put your thumb over it, then divide whatever is still showing below the line into the quantity on top.
- Your numbers have to already be in the units printed on the wheel — convert first.
- Metric appears in parentheses wherever it differs from the US value, like (m²).