How it works
Nico wants a new kite, and three shops on Kite Street sell the very same one. A huge sign shouts "Sale!" at the Big Toy Shop.
A sale sign tells what comes off. It is not the price. The price is what is left, so take it off first.
Then compare the prices you would really pay. Half off means two equal parts, and half is one of them: half of 8 is 4.
Sales can be great, as long as you check the price you pay.