Lesson 1 #7

First you need to determine what operation needs to be performed based on the context of the problem.  The list below describes a lot (but not all) of the types of problems you'll see

1.  Combining 2 or more quantities?          Addition

2.  Adding on a quantity to some amount you already have?          Addition

3.  Finding the difference between two quantities?          Subtraction

4.  Taking one quantity away from another?          Subtraction

5.  Making some quantity of copies of another quantity?     Multiplication

6.  Repeatedly adding a number to itself some amount of times?         Multiplication

7.  Breaking a quantity into equally sized groups?         Division

8.  Repeatedly subtracting an equal quantity until you reach zero?       Division

In this problem, you can imagine making 11 copies of the cases each with 18 reams of paper.  So this problem is like 5 listed above which makes this a multiplication problem.  

One way to compute this is to use the standard algorithm.  Let's try another way.

If I had 10 cases with 18 reams of paper, this would be 10 x  8 = 180 reams.  Since I have 11 cases, I have one more case than this which means I have 18 more reams.  Adding these quantities together gives 180 + 18 = 198 reams of paper.

Now view the standard algorithm below.  Can you see how these numbers relate to the quantities described above?