Useful quick reference MM to Inches Chart:
The first two columns show millimetre measurements on your 1/32 slot car and what they represent in inches on the real 1/1 car. The next two columns show inches on the real 1/1 car and and what they represent in millimetres on your 1/32 slot car.
So, the number 10 in the left of the first two columns shows that a measurement of 10 mm on your 1/32 car represents 12.6 inches on the real 1/1 car.
Similarly, the number 10 in the left of the second two columns shows that 10 inches on the real 1/1 car is represented by 7.9 mm on your 1/32 car.