Warm up by picking some random numbers and counting up in 1s, 10s, 100s and 1000s
Example:
Count in 1s from 3540
3540 3541 3542 3543 3544
Count in 10s from 3540
3540 3550 3560 3570 3580
Count in 100s from 3540
3540 3640 3740 3840 3940
Count in 1000s from 3540
3540 4540 5540 6540 7540