I am currently developing an incremental game using gold as currency. However when you buy an item that gives gold per second after three seconds it starts giving values such as 4.1000000000000005 for player gold.

This is my function I have set to calculate player gold by adding the gold per second value every second:

setInterval(function() {
player.gold = player.gold   Math.round(player.gold_per_second * 100) / 100;
player.lifetime_gold = player.lifetime_gold   Math.round(player.gold_per_second * 100) / 100;
update_view();
}, speed);

I have read somewhere that by multiplying player.gold_per_second by 100 then dividing it by 100 would eliminate floating point rounding errors however it hasn't done anything for me.