human body muscles

Most electrical appliances have wires attached to them.
The wires carry an electric current around a complete pathway called an electric circuit.
Some appliances need more electric current than others before they will work.
The amount of electric current depends on how much electricity is flowing along the wires.
How can we measure the amount of electric current?
We could try counting the number of electrons that pass along the wire each second.
But this wouldnt be easy!
There are a huge number of electrons traveling along most electric wires.
About 3 million million million electrons flow through a flash bulb every second!

To make it easier, we measure the flow of electric current in amperes. 

The word ampere comes from the name of the French scientist Andre Ampere, who invented a way of measuring electric current.

We usually say amp instead of ampere. 

One amp is equal to about 6 million million million electrons every second. So a flashbulb would have a current of half an amp flowing through it.
Thats much easier!
Scientists use a special measuring device called an ammeter to measure the electric current.
The ammeter is connected into an electric circuit so that the electrons flowing around the circuit also flow through the ammeter.