Abdul is saying “I have nine shells.” And Amy is saying “I have three more shells than Abdul.” How many shells does Amy have?
From the information that we’ve been given, we know that both Abdul and Amy have got some shells each. And we need to work out the number of shells that Amy has. We already know how many shells did Abdul has because he tells us. He says, “I have nine shells.” Amy doesn’t tell us how many shells she has. But she does give us a clue. She tells us that she has three more shells than Abdul.
So to find out the number of shells that Amy has, we need to work out the answer to nine plus three. What is three more than nine? We can just count on three from nine to find the answer, nine, 10, 11, 12. We know that nine plus one equals 10. And if we add another two, this will take us to 12.
If Abdul has nine shells and Amy has three more shells than Abdul, we know that Amy must have 12 shells. 12 is three more than nine.