Dave collect rocks. he makes 12 groups of 10 rocks and has none left over. hove many rocks does dave have?

He makes 12 groups of 10, so you have to multiply 12 by 10, and you get 120 rocks. If you still don't get it, maybe this will help:

                         
           

           
           
                

I did 12 groups of "rocks" and if you count them, you get 120.

You multiply the number of groups dave has by the number of rocks in each group. 

12*10= 120 rocks 
therefor dave has a total of 120 rocks

This is too long-standing now get out