I have a boy, he has a toy which need 3 batteries, but I only have 2 batteries. With an easy hack I can switch on the toy to work properly. What did I do?
Directly connect one of the terminals to the opposite terminal with a strip of metal?
This could potentially not give the toy enough power, stopping it from working.
Based on the tag for this question,
Use a small, reasonably shaped potato / similar root vegetable(s) and join them with external wires to have the required power of 3 batteries.