if you don't know how to round up or down?
Tell us the name and location of your store so we can stay the hell away.

mind blowing on how many people don't know how to make change or count or know what a nickel is wtf? you don't pay with money so you don't know how to use it, i work retail simple math and knowing the difference between a nickel and a quarter

And have no business handling customer cash.

In two different cafes, I have had staff unable to calculate 50 minus 25.
It's not that it's so hard that's pathetic, it's you.

You don't need to do any math.
If someone passes you a fifty dollar to pay for a $34.52 item, count it *back up* to fifty dollars.
(Round down so it's 34.50 they owe - it's less than 3 cents)
Hand it out:
Here's two quarters to make it $35, a fiver to make it $40, and a ten dollar bill to make it $50.
Done, you just gave them their $15.50 in change.
My Dad told me to try that when I was young, new at a job and a bit anxious about going blank if put on the spot. It worked.

Smart phone reliance and over usage follow by denial and withdrawal. Too bad you don’t work in a bank.

When you drop out of Grade 5

...got my grade ten!

Due to the technological advances of the majority of cash registers that are all computerized, cashiers no longer have to actually think. They just have to key in the dollar amount of cash that the customer gives them and it will tell them how much change is due. Unfortunately it appears that the Op hasn’t even got the capacity to do that....

there's youtube how-to videos about how to count change. maybe try watching some of them.