What's your favorite subject at school? Don't say lunch or recess! Those are everyone's favorites! When it comes to popular subjects, some students prefer English. Other students may like science or history. Kids with a head for numbers may find math to be their favorite class of the day.

As you get older, your math classes get more challenging. If you've experienced algebra or more complex subjects, such as geometry, trigonometry, or calculus, you know that you quickly move beyond calculations that you can do in your head.

For more advanced mathematics subjects, a calculator is an absolute necessity. When you think about pioneers in the fields of mathematics, their achievements seem even more impressive when you realize what they accomplished without the help of calculators or computers.

But what about the earliest humans on Earth? Even before calculators and computers were invented, mathematicians had developed number systems to work with. The earliest human beings didn't have language, let alone number systems to do basic math. So how did they keep track of things?

Before number systems, counting was likely accomplished the same way you learned to count: with your fingers and toes! Early man undoubtedly quickly realized that a means of counting beyond 20 was necessary.

The earliest humans likely turned to objects in nature surrounding them to help keep count. Rocks and sticks could easily be used to count and keep track of objects. When basic trade began, however, early merchants needed a device to help them make basic calculations and count large numbers.

The first counting devices were likely made of grooves carved in sand or wood in which small objects, such as beads and pebbles could be moved. Over time, these devices were created as a frame made of bamboo or wood with rods, strings, or wires that had beans or beads that would freely slide on them.

This early device was known as the abacus or counting frame. If you have more than one abacus, they're called abaci or abacuses. A person who uses an abacus is known as an abacist.

The abacus was used for centuries before modern written numeral systems were created. Despite advances in modern technology, abaci are still used frequently today by merchants and traders throughout Asia and Africa.

Although no one knows for sure when the abacus was first invented, historians know that various versions of abaci showed up in different cultures at different times throughout history. For example, the Sumerian abacus may have been the first abacus invented as early as 2700 B.C. Over time, versions of the abacus were used by the ancient Persians, Greeks, Romans, and Chinese.

If you've ever used an abacus, you know that beads can be moved to a different position to keep track of counted objects. Different abaci have different configurations. More complex abaci allow users to add, subtract, multiply, and divide.