big.js VS autohotkey-scripts

ii) Third-Party Libraries There are various libraries like math.js, decimal.js, big.js that solve the problem. Each library functions according to its documentation. This approach is comparatively better.

For financial applications, APIs commonly return currency values, balances, stock/currency positions, and other amounts as strings. The best way I've found to deal with this is to use a library like big.js.

Just for fun, using javascript library:

Another different approach maybe to have the money represented in the decimal in your database at the decimal places of the currency with the highest decimal point you are going to be dealing with for example using Decimal(n, 2) in case of fiat, and perform your calculations in arbitrary-precision Decimal type. In javascript, using libraries like Big.js , Decimal.js will be of help.

With that said, using a library like big.js will solve both this and the potentially unsafe eval use:

It will explain this weird behavior. You have to use a special lib for precise floating point math. Here is one: big.js.

From a forum post, it looks like you could use Aviaryan's ScientificMaths library (documentation), which is using strings.