Adding machine

This adds in pounds shillings and pence. It only has the numbers up to 5 so if you need to add 8 you have to do 4 twice or 5 then 3, etc. My son wanted to take it apart but I said no. It works perfectly fine now but I'm not sure if he would be able to put it back together. The extreme right hand number goes up to 11 for the pence. The third column only has one button for ten shillings.