初中英语牛津八年级上学期04（2）
On the abacus in the picture,
the beads on the wires represent ones, tens,hundreds and thousands
starting from the bottom wire.
The picture on the right shows a modern electronic calculator.
It can add,subtract, multiply and divide.
It can also calculate percentages and square roots.
This picture shows a computer.
Computers are very powerful calculating machines.
In a flash, a computer can do a calculation
that you could not do in your whole lifetime
Brain against computer Some people call the brain a living computer.
Is a human brain a more powerful calculator than a computer?
The following story may give an answer.