5 digit calculator

this is a calculator I built and it turned out great! this is my first creation that didn't use pistons and i am happy! it also color coded so here's the key:

RED: input
DARK GREEN: memory
LIGHT GREEN: bridges
BROWN: output

this is a slow calculator and is quite big so if 2 lights flash on it is just loading so wait a sec. to add just flip the switches above the numbers you want to add. you can only add 2 numbers at a time or it will not work. so have fun adding numbers or setting it on fire!