๐ Inventions and machines ๐ง Machines and tools
Calculators
๐ In short
A calculator is a small device that adds, subtracts, multiplies and divides quickly and accurately. People use it in shops and offices, and engineers and scientists use it to solve hard problems. Your phone and computer have a calculator too.
๐คฉ Did you know?
- The abacus is one of the oldest calculating tools in the world.
- Some calculators run on sunlight.
- Scientific calculators work out roots, fractions and angles.
- The first electronic calculators were as big as a typewriter.
๐ Find out more
๐ The old abacus
Long ago people counted on their fingers and with pebbles, then invented the abacus, a frame with beads that slide along wires, and some children still learn arithmetic with it.
๐ Machines with gears
About 400 years ago the French scientist Pascal made a calculating machine with toothed wheels that added and subtracted numbers when the wheels were turned.
๐ก The electronic calculator
Today a calculator has a tiny electronic chip that does the sums and a screen that shows the numbers. Some run on a battery and some on a small solar cell.
๐ฏ Your brain first!
Calculators are useful, but it's important to learn to calculate in your head first, so you know if the answer makes sense, and your memory and mind get stronger.
๐ธ More pictures
๐งฉ Test yourself
1 What old tool has beads for counting?
2 What do some calculators run on?
3 About ?? years ago the French scientist Pascal made a calculating machine with toothed wheels that added and subtracted numbers when the wheels were turned.
4 Which picture shows โCalculatorsโ?
๐ Discover more
๐ท Picture sources: Wikimedia Commons
- Mc681 ยท CC BY-SA 4.0
- NJR ZA ยท CC BY-SA 3.0
- Thomas Schanz ยท CC BY-SA 3.0
- Evan-Amos ยท Public domain
