Ann is grouping 38 rocks. she can put them into groups of 10 rocks or as single rocks. what are the different ways ann can group the rocks?

The answer to this question would be: 4 different ways

It will be easier to answer this question by making a list of the possible way. In this question, the group is either 10 rocks or single rock. Then the list should look like this:
1. 3 groups of 10 rocks + 8 groups of single rock
2. 2 groups of 10 rocks + 18 groups of single rock
3. 1 groups of 10 rocks + 28 groups of single rock
4. 0 groups of 10 rocks + 38 groups of single rock

Yo no me sé esa mala mia