By using this site, you agree to our Privacy Policy and our Terms of Use. Close

0.333.... = 1/3
3*.3333= 3*(1/3)= (3*1)/3
0.999.. = 1

Or

0.111... = 1/9
9*0.1111..= 9*(1/9)= (9*1)/9
0.999.... = 1

Or

x= 0.999...
10x = 9.999...
10x - x = 9.999... - 9.999...
9x = 9
x=1
1 = 0.999...

Or

0.999... = 9(1/10) +9(1/10)² + 9(1/10)³ + .... = (9(1/10))/(1-(1/10))=1