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Operations and calculations

3. Subtraction

3.6. Everyday activity

Calculating electricity or gas usage

Subtraction is an operation you can use to work out how many units of electricity or gas you have used since the last reading you submitted your last reading.

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 the difference between the two readings. To find the difference, subtract the previous reading from the current reading.

A meter with the reading 50682 displayed within the first 5 boxes and a 1 in the red box on the right

Try it out

How much electricity has been used since the last meter reading?

160 KWh has been used.

Subtract the previous reading (50522) from the current reading (50682) to find the difference:

50682 - 50522 = 160