Remember, when you count by 1 (one) the numbers get bigger by 1 (one). It is like you add 1 every time you count up. Example:
0+1 = 1
1+1 = 2
2+3 = 4
The numbers would be:
1,2,3,4,5,6,7,8,9,10,
11,12,13,14,15,16,17,18,19,20,
21,22,23,24,25,26,27,28,29,
30,31,32,33,34,35,36,37,38,39,...,100
You can look at this video and enjoy yourself counting by 1