It means having more than one digit. In the context of decimal integers it means a number greater than 9.
the digit before the decimal point in decimal notation, representing an integer less than ten.
what does key mean in math
I do not know of such a word related to math(s)
There is no such math word, so it does not mean anything. You may wish to check your spelling before posting questions!
A single character standing for a number. In the decimal system (base 10) it always stands for a single numerical character: 0,1,2,3,4,5,6,7,8 or 9. But that need not always be the case. For example, B is the hexadecimal digit representing 11.
the word by means 'times' or 'multiply'
The word at means the least
its mean like well its a math term its like distrubed fractions