Discuss the idea of recognizing math problems using the context of a bus ride. Tell students that using the context of a bus ride helps them to understand situations that involve addition and subtraction. Explain what it means when things are added, or taken away (subtracted) and that the signs + and - are used. Explain to students that the + tells us that passengers were added to the bus, and that there are now more passengers on the bus. Continue by explaining that the - tells us that passengers were subtracted from the bus (or exited the bus) and that there are now less passengers on the bus. Show students how to recognize addition in a bus problem. Show students that on the bus on the left, there are 2 passengers on the bus. The bus stops at the bus stop, and when it leaves, shown by the bus on the right, there are 4 passengers. 4 is more than 2 which means that there are more passengers than when they stopped, which means that passengers were added. Then show students how to recognize subtraction in a bus problem. Show students that on the bus on the left, there are 2 passengers on the bus. The bus stops at the bus stop, and when it leaves, shown by the bus on the right, there is only 1 passenger on the bus. 1 is less than 2, which means that there are less passengers than when they stopped, which means that passengers were subtracted (or exited the bus). Practice adding to and subtracting from on the next two pages. Each page shows three images, a bus on the left with passengers, an empty box in the middle, and a bus on the right with passengers. Look carefully at how many people are on the bus on the left and on the right and decide as a class if passengers were added to or subtracted from the bus. If passengers were added to the bus, drag a '+' sign to the empty box in the middle. If passengers were subtracted from the bus (exited) drag a -'' sign to the empty box in the middle. Then practice adding to and subtracting from by circling the correct bus on the right. On the left there are busses with passengers, in the middle there is a '+' or '-' to show if passengers were added or subtracted. Only one bus on the right can be correct and should be circled. Repeat this, but in the next exercise you can't count the passengers because they are represented by a number.

Check that students are able to recognize addition and subtraction situations using the context of a bus ride by asking the following questions:

- Where do you look to see if it is an addition or subtraction problem?

- If there are three passengers on the bus, and then after the bus stop, there are five passengers on the bus, is it addition or subtraction?

- Can you give an example of a bus problem with subtraction?