Fifty-one.
To write the number 51, you simply use the digits "5" and "1" together. In words, it is written as "fifty-one." In Roman numerals, it is represented as "LI."
51 = LI
51/100
51 hundred equals 5,100
0.51 is 51 hundredths as a decimal.
51/25 = 2.04
51 hundredths written as a decimal is 0.51
5,100
34/51 = 2/3
51/40 written as a decimal is 1.275
51/1000
LI