

The Babylonian numeral system is the oldest known positional numeral system. The number 352 is pronounced three zeek five azeka two. After 5 comes 'zeek' and after 55 comes 'azeka'. They have 6 fingers total and use a heximal (base 6) system. In the octal system, the value of each digit is a power of 8. The octal number 45 has the decimal value 4 × 8 + 5 = 37. A 7 is incremented to 10, 17 to 20 and 77 to 100. In the octal system it also works like this. In the decimal system 9 is incremented to 10 and 99 incremented to 100. The number 5342 is pronounced five block three board four oct two. For this reason the teacher is also able to recognise gaps in the thinking process with the (decimal) positional system. You cannot rely on your memory anymore, but really have to use arithmetic. It teaches the children abetter insight into the workings of a positional system. In the country of Oct people have eight fingers so they use the octal system. In (Dutch) primary schools this numeral system is sometimes taught as: 'Het land van Oct', which translates in 'The country of Oct'. The octal number system is a base-8 positional numeral system. In our example this will look like this: 10011101 2 = 157 10. To avoid confusion you can use a subscript number to show in which number system the number is written. If necessary, compare this to the table for the decimal positional system at the top of the page.

In the binary number, the value of each digit is a power of 2. In the binary system it also works like this, as there is only 0 and 1 a 1 is immediately incremented to 10 and 11 incremented to 100. The binary number system is base-2 positional numeral system.Ī binary number with eight bits is called a byte. If you strictly uphold all rules, the biggest number possible is MMMCMXCIX = 3999, as you can only use M three times in succession. You then also have I, II, III, IIII (= four numerals with I), V, VI, VII, VIII (= four numerals with V) and IX, X, XI, XII (= four numerals with X). IIII is as wide as VIII, which is on the other side on the clock. An other reason can be that IV is often upside down on a clock. The most heard explanation is that IV were the first letters of Jupiter (IVPITER in Latin) and therefore not used. On clocks you often see IIII instead of IV for four.

A symbol can only be subtracted from a symbol that is five or ten times bigger, so not IC but XCIX V, L and D are not used to subtract, so not VC but XCV.

At most one lower symbol in front of a higher symbol.Īnd these two rules that are not always taken in to account: At most three times the same symbol in succession. The following rules are added later, to get an unambiguous system: The numbers are written from high to low. V, L and D are only allowed once in a number. In that case the lower value is subtracted from the higher value. The original rules were that the value of individual symbols are added unless a symbol with a lower value comes before a value with a higher value. The system has no symbol for zero and does not use negative numbers. The Roman numeral system is the most well-known system that is not a positional system. Looking for an explanation about our regular numbers? Look at decimal numbers. Arithmetic » Roman, binary, octal and Babylonian numerals
