Lesson 1 #6

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

Once you determine the operation(s), you need to perform the computations. This problem is like 3 listed above. For this subtraction problem, you are comparing or finding the difference of the two different quantities of customers.  

Since we want how many more customers on the weekdays, we will subtract the weekend quantity from the weekday quantity.  

Another way to state this subtraction problem is the weekday quantity minus the weekend quantity. 

Notice how the order of weekday and weekend changes in the two descriptions above, but that we are computing the same amount in the same order.  Order matters in subtraction! These both mean 14822 - 13562.

One way to compute these is to line them up vertically and borrow when necessary as shown below.