Using the three images of busses on the interactive whiteboard, explain to students how the bus method works. You first count the passengers on the arriving bus, then you count the passengers waiting for the bus, and then you know how that the total number of passengers leaving with the bus is the first two numbers combined. The first addend of the problem is the number of passengers in the bus as it arrives to a stop. The second addend is the amount of passengers waiting for the bus at the stop. The total, or sum, is the combination of the two addends. Show this with an example where you first count to 10 and then continue counting on. Discuss two more bus problems where you can count the individuals from the image presented.

Tell the students that the image will now stay the same, that you can show a bus problem in one picture, and practice this with two bus problems. Next show students a bus problem in which they cannot count the passengers, but are given an abstract number. Explain that the first number is the first addend, the number of passengers on the bus, the second number is the second addend, the number of passengers waiting to get on. With this example, be sure to emphasize that students can add to 10, and then count on to make their addition easier. Practice the bus problems with abstract numbers as a class.

Check that students understand addition to 20 with bus problems by asking the following questions:

- Which steps do you take to solve a bus problem?

- Is the number of passengers on the bus the first or second addend?

- What do you do with the passengers that get on the bus?