Hi Marissa. In order to solve this problem, I think you should try this approach.
First draw 12 cars and add 4 tires to the cars. Then count how many tires are there in total. After that, you can add 12 to that sum and you will have your answer.
You can also use the process of repeated addition, which is when you add the first number (in this case 12) the number of times the second number specifies (in this case 4). The process is shown below:
12+12+12+12=48
Then you can add 12 to the sum shown above, to represent the 12 spare tires the owner got:
48+12=60
I hope this was helpful for you, Marissa. If you need any additional help, please feel free to contact me through Wyzant.
