How much money did the owner lose?

$200 or a bit less.

$100 from the theft
$ 30 in change
$ 70 for the value of the goods (although technically a little less because owner bought the goods at a discount and marked up the price to $70).

For all intents and purposes the owner is out close to $200.

But the $30 in change came out of the original $100, so that would be $170.

I tried arguing the COGS too, but many people said that was invalid. It was all about the cash money, not the nebulous cost of goods. I also wanted to claim the profit but many argued no, just the cash…...they claimed they paid attention to the “details.”

The thief steals $100. Then he gives it back and steals $30 and goods valued at $70. But, as @elbanditoroso pointed out, they were marked up. So, ultimately, the thief has stolen less than $100 in goods and cash.

The store owner is out $100 from an accounting standpoint.

Separate into two transactions. In the first, the cash drawer is short $100.

In the second transaction, the store owner has sold $70 worth of goods and the cash drawer shows +$70 and the inventory of the store is -$70. There is no loss on the sale.

But when you do the books you have to account for the other transaction that gave him the $100 to begin with, before it was stolen.

Thief removes $100 from till
Thief returns hands back it back, owner puts $100 in till
Net = $0.00 (as of this moment)

Thief leaves with $30 cash + $70 goods
Net = $100 loss

At least 170.

@Dutchess_III I did that. That is why the loss is $100. There is no loss on the sale of $70 worth of goods.

I know. If we’re dealing strictly with the cash there was no loss on the goods. Or the profit. So I agree with you.

$100. You didn’t ask for anything but lost money. The guy took $100 so that is all the money the shopkeeper lost. The fact that something was bought with the money is a red herring.

Well, for someone who has never owned a business it’s a red herring. It’s so ingrained in me I can hardly separate the two.

The owner has lost $100.

1. All the transactions were legitimate apart from the theft of $100, so $100.
2. Or, if you consider that the guy walks out of the store with $70 of goods and $30 in cash that he didn’t have before it is also $100.