Transactions always balance. Money always comes from somewhere, and it always goes to somewhere. Total debit always equals total credit.
In a double entry accounting system you have to say where that $200 came from.
Did it come from a sale (you sold your work, an item), a loan you took, someone you loaned money yourself, or an investment in your company.
In double accounting it always balances.
Here I am talking debit and credit because this is nothing to do with my point about positivity or negativity. This is how double entry bookkeeping works.
If you make all the numbers positive, then the total credit has to equate ('balance') with the total debit.
So treating debit as negative and credit as positive, means 'balancing' is just summing to 0.
Before double entry bookkeeping was invented in the Renaissance, single entry accounting just kept separate lists for all things. This works for basic tracking of money. For individuals particularly. But has massive weaknesses for tracking where money is coming from how it moves around, and making sure there aren't errors. Money doesn't come out of the blue. Which is why it is the business standard. And the legal requirement in most of the world. One of the most amazing and significant human innovations, IMO.
The credit and debit/what to add/what to subtract rules are only because double entry accounting was invented before use of negative numbers (they were only a weird mathematical curiosity at the time).
So I am not reinventing anything.