An abacus. The bottom line is ones, the second is tens, and etc. Basically, it was an ancient calculator.
An abacus (or soroban in Japan)
Calculating is manipulating numbers. It may be done manually on pen and pare, on the computer, or on a traditional calculator.
The counters are for destinations depending on the last bound and direction. In 2015, they were 14, For 2017m no idea. One have to be in the station to count it manually. No other way to know the numbers (e,g from web, statistical bureu)
Use a calculator if you can't do the math manually.
Break it Push the ON/C , the 5 and 6 buttons simultaneously
Use the link provided to University of Arizona math page where the algorithm is explained.
You can't 'get rid' of them - if the problem creates them in the answer. You can, however, manually round the answer up or down to a more manageable figure.
shunt trip coil used to trip the breaker automatically or manually.
Bankrate offers a free online loan calculator, as does the Calculator website. Alternatively, one can do the calculations manually; with an initial value of A and an interest rate of B per year, the value after C years is A*(1+B)^C, where the "^" represents exponentiation.