Arithmatic conversion and store binary of a number

Question

I read this article:

The Patriot Missile Failure

I have one question: in above article it said that:

It turns out that the cause was an inaccurate calculation of the time since boot due to computer arithmetic errors. Specifically, the time in tenths of second as measured by the system's internal clock was multiplied by 1/10 to produce the time in seconds.

Why it should multiply by 1/10 not 10? if we have 0.1 second and it multiply by 1/10 then it equals to 0.01!

Have a good time

Answer 1

The system is counting the number of tenths of seconds that have passed. One tenth of a second is $1$, two tenths of a second is $2$, three tenths of a second is $3$, etc. To convert that number to seconds you multiply by $1/10$.