Explanation:
When I was a kid, the inch was a different length than the inch of today. Back then, there were approximately 39.36 inches in one meter. I had no trouble memorizing that number and still use it today, even though the number today is actually 39.37 inches (plus a tiny amount extra).
Today, the inch is defined to be exactly 2.54 centimeters long, so if we want to know exactly how many inches are in the meter, we would divide the number of centimeters in one meter by the number of centimeters in one inch.
[math]\frac{100\,cm\,per\,meter}{2.54\,cm\,per\,inch}\,=\,\frac{100}{2.54}[/math] inches per meter
My Windows calculator says that this is equal to:
39.37007874015748031496062992126…
I recommend memorizing the number 39.37.
As long as you memorize the fact that there are 2.54 centimeters in one inch, you can always use your calculator to get the approximate number of inches in one meter.
Addendum:
The old Mendenhall inch (1893) was exactly 39.37 inches per meter. The international inch, 0.0254 m, gives 39.37 and a bit. Total change is 2 parts per million.