toFixed(): the rounded representation is a string

Useful to know

toFixed() returns text with a given number of digits after the decimal point. For example, (2.5).toFixed(2) is "2.50", and not the number 2.5 with any reserved zeros . [1]

Use the score for performance, not as a basis for accurate financial accounts. Some decimals do not have an exact binary representation, and this affects the rounding. If you then add formatted strings with +, you might get a clump of text. Compute with a suitable data model and format the border with the interface.