Round to the nearest tenth of a meter?

To round a number to a particular digit, look at the digit immediately to the right of your target, in this case, the hundredths place. If that digit is 4 or lower, zero it and everything to the right of it out. If that digit is 5 or higher, increase the target digit by one and zero everything to the right of it out. If your target digit is a 9, increasing it will turn it to zero and increase the digit to the left of it by one.