Decimal system and Positional notation

Decimal system noun - A positional system of numeration that uses decimal digits and a base of ten.

Positional notation and decimal system are semantically related. In some cases you can use "Positional notation" instead a noun phrase "Decimal system".

Positional notation noun - A numeration system in which a real number is represented by an ordered set of characters where the value of a character depends on its position.

Decimal system and positional notation are semantically related. Sometimes you can replace phrase "Decimal system" with "Positional notation", this phrases are similar.