One layer of cubes, then stack the layers. That is all volume ever is.
Length · Width · Height
Enable JavaScript in your browser to calculate.
The metric staircase. Every step is ten, so converting is just sliding the decimal point.
Inches, feet, pounds, cups. No pattern to lean on — so go down to the smallest unit and back up.
Count on to the next whole hour, then the hours, then the leftover minutes. Works every time.
The two get mixed up constantly. One is the walk around the edge, the other is the space inside.