Twice means two times
Let x be the number
twice the number = 2x
2x = 918
Divide both side of equation by 2
2x/2 = 918/2
x = 459. This number is an odd integer because it ends in 9.
Do you know that odd integers are numbers with 1,3,5,7,9 in their ones digits?
And even integers are numbers with 2,4,6,8,0 in their ones digits. :-)