Everything at Once

A long line is worked one rank at a time, and each line you write does one small step. Here is (5 - 2 × 4)^2 / 3 - 4. The board writes the division as a fraction bar, with the power on top and the 3 underneath.

Inside the parentheses the product goes first: 2 × 4 is 8, giving (5 - 8)^2 / 3 - 4. Finishing the parentheses gives (-3)^2 / 3 - 4. Now the power: (-3)^2 is 9, positive because the exponent is even, so the line is 9 / 3 - 4. The division gives 3 - 4, and the subtraction, last of all, gives -1.

The fraction bar groups its top, so the whole top, power included, is finished before you divide. Five short lines may feel slow, but each one is easy to check.