Use a for loop to cycle over a fixed range of numbers.

for i = 1 to 3
  Print (i)

1
2
3

for i = 5 to 12 step 2
  Print (i)

5
7
9
11

for i = 20.0 to 15.0 step -1.5
  Print (i)

20.0
18.5
17.0
15.5

For testing purposes, you can of course also type a loop directly into the console. Just make sure to keep the indentation (the first loop iteration will execute while you type) and close the loop by typing a command without indentation:

>for i=1 to 3
>  Print (i)
1
>  Print (i*4)
4
>Print 'Done'
2
8
3
12
Done