Handling Large Decimal Numbers (200+ digits/decimals) in TypeScript: String vs Number and parseFloat() Conversion

Question

I'm working with very large decimal numbers in TypeScript that can have up to 200 decimal places. Currently, I'm storing these numbers as strings to preserve precision.

const largeDecimal: string = "123.456789012345678901234567890..."; // 200+ decimal places

I have two main concerns:

• Is using string the correct approach for storing such large decimal numbers?
• In situations where I need to perform calculations, what's the best way to convert these strings to numbers? Should I use Number() or parseFloat()?

// Which approach is better?
const usingNumber = Number(largeDecimal);
const usingParseFloat = parseFloat(largeDecimal);

What I've Tried

I've attempted both conversion methods, but I'm concerned about potential precision loss:

const sample = "123.456789012345678901234567890";
console.log(Number(sample));     // 123.45678901234568
console.log(parseFloat(sample)); // 123.45678901234568

Questions

1. Is storing these large decimals as strings a good practice in TypeScript?
2. What's the recommended way to handle numeric operations with such large decimal numbers?
3. Are there any built-in TypeScript/JavaScript solutions, or should I consider using external libraries?

Environment

TypeScript Version: 5.x Node.js Version: 18.x

Any insights or best practices would be greatly appreciated!