The computer is a useful machine. It is the most important invention in many years. The oldest kind of computer is the abacus, used in China centuries ago, but the first large, modern computer was built in 1946. A computer then could do maths problems quite fast.

Today computers are used in many ways and can do many kinds of work. In a few years the computer may touch the life of everyone, even people in faraway villages.

In the last few years, there have been great changes in computers. They are getting smaller and smaller, and computing faster and faster. Many scientists agree that computers can now do many things, but they cannot do everything. Who knows what the computers of tomorrow will be like? Will computers bring good things or bad things to people? The scientists of today will have to decide how to use the computers of tomorrow.

Today anyone will accept money in exchange for goods and services. People use money to buy food, furniture, books, bicycles and hundreds of other things we need or want. When they work, they usually get paid in money.

Lots of the money today is made of paper. But people used to use all kinds of things as money. One of the first kinds of money was shells. Shells were not the only things used as money.

In China, cloth and knives were used. In the Philippine Islands, rice was used as money for a long time. Some Africans once used elephant tusks, monkey tails, and salt as money.

The first metal coins were made in China. They were round and had a square hole in the center. Different countries have used different metals and designs for their money. Later, countries began to make coins of gold and silver.

But even gold and silver were inconvenient if you had to buy something expensive. Again the Chinese thought of a way to improve money. They began to use paper money. The first paper money looked more like a note from one person to another than the paper money used today.

Money has had an interesting history, form the days of shell money until today.