Each month Kyler buys a pack of 8 replacement tires.
He does this for 2 months.
At the end of each month he has 1 tire left.
So the numerical expression for the number of tires he uses per month will be;
Number of tires used in 1st month = 8-1 =7
Number of tires used in the 2nd month = 8 - 1= 7
Total number of tires used in two months = 7*2 = 14
Tires left in two months = 1+ 1 = 2
Comparison : The number of tires used in two months is twice that used in one month.