A steady flow rate is checked as area multiplied by speed. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Flow rate is area times speed
Area 2 square metres and speed 3 metres per second give flow 6 cubic metres per second.
Q=2×3=6
The flow label is source-bound
The flow value 6 comes from the displayed area and speed sources.