This repo is not maintained. Go here https://github.com/gauravnumber/math-code
Actually math-code simple a javascript program can do calculate large digit value.
What is the value of 83247834928749827394872398472983749823749823794872398472938749823749823674623748237 * 8676378326376283.7283232389999999999999999999999999999329392839789238
If you type these number in calculator answer show in scientific notation but what is the exact value of these calculation.
So, you use math-code.
Answer is 72228971069355556238693946799266498315999628309725866340973861164532852078428645819038442204359796.683951471030119766629511096878039024570233613871940685207842864581788900992588763966990834365019311679791113404706643788919372654073406