"Count by ones" meaning is if you start at 1 and stop at 10, you've to count all the numbers within the area one by one. 1-10 Count by ones : 1,2,3,4,5,6,7,8,9,10
So Andy starts at 29 and stops at 45, then he will say 29,30,31,32,33....,45
So answer for the problem is, he will say 29,31,35 and 40