Multiplication is an operation you can use to work out the cost of the electricity or gas units consumed since the last reading submitted.

For example, this meter is currently reading 50682 (the number in the far right (red) box can be ignored).

The previous reading submitted was 50522.

The amount of units used is 160, which is the difference between the two readings (50682 - 50522 = 160).

Multiply the usage by the charge per kWh to find the cost of the electricity used since the last reading submitted.