Math In Medieval Times

Math Using An Abacus

The abacus is a mechanical aid used for counting. Addition, subtraction, division and multiplication can be performed on a standard abacus. However you are we will onluy be working with addition and subtraction. And now get ready to learn the basics. Calculations are performed by placing the abacus flat on a table or one's lap and manipulating the beads with the fingers of one hand. Each bead in the upper deck has a value of five; each bead in the lower deck has a value of one. Beads are considered counted, when moved towards the beam that separates the two decks. The right-most column is the ones column; the next adjacent to the left is is the hundreds column, and so on. After 5 beads are counted in the lower deck, the result is "carried" to the upper deck; after both beads in the upper deck are counted, the result (10) is then carried to the left-most adjacent column. Floating point calculations are performed by designating a space between 2 columns as the decimal-point and all the rows to the right of that space represent fractional portions while all the rows to the left represent whole number digits.
Now it's your turn to use a real abacus. Just click on the abacus below and begin to add or subtract. Have fun!

Interested in Making Your Own Abacus? Click here.

Create An Abacus

Roman Numerals

The ancient Romans invented Roman numerals. These numerals were used by people throughout Europe until the 1500's A.D. At this time, people began to using Arabic numerals. Roman numerals have seven symbols that stand for numbers:
I=1 V=5 X=10 L=50 C=100 D=500 M=1000
They did not have a symbol for zero. You read Roman numerals from left to right. The Romans added and subtracted combinations of the symbols to write their numerals. Here's how they did it.
A smaller number before a larger one means subtraction:
IX (1 before 10)=9
A smaller number after a larger one means addition:
VIII (three 1's after 5)=8

Go here to find out about Medieval Currency.