The TLDR is that what kind of number you require depends on what kinds of operations you need and to what extent their result must be correct. If you require that all addition and subtraction gives a comparatively correct number (A + 1 == A where A is a very big number must ALWAYS be false), then you have to use a big integer like one from BigInt. If you try to use a float for this, then A + 1 will â€śflushâ€ť if A is too large, and the result will be unchanged. However, if the numbers youâ€™re adding to A grow at about the same rate as A itself, you can continue to use floats up to almost their maximum value of about 10^33