Question

chris has 5 stack of dvd each stack has10 dvds if chris add 2 more identical stacks of dvds to the shelves how many dvds will chris have

Answer 1

first if each stack has 10 cds and there is 5 stacks you do 10 X 5= 50. then you add two more stacks of 10 ( 2 stacks of 10=20) and add 20 to 50 which is 70