if a hotplate is on the ground and full of batteries, you can pick up “part” of the hotplate by typeing a number, creating a hotplate with that many batteries and leaving that ammount fewer batteries on the counter. this bug is wierd as hell btw.
further testing shows that the bug exists for other electronic devices. in addition, picking up a bottle of water after pressing 1 will allow you to pick up the bottle normally, but also spawn an empty plastic bottle in the pick up spot. i have no idea WTF.
furthurmore, attempting to pick up the plastic bottle after pressing one doubles the plastic bottle and leaves one behind. i will test if it works the same way for other items, and whther pressing other numbers has any effect.
edit: it works the same for other items and it doesnt seem to matter what number i press. it does matter that i press the number before i pick up the item in the pickup screen.
edit: for items that are actually stackable, like bandages, picking up part of the stack merely splits the stack as expected. it works properly even if there is only one item left in the stack. this appears to be the only case where the #pickup works properly. presumably somebody programmed a way to pick up and split stacks, and didnt consider the consequences to non stacking items.