Small math utility that gets the basic arithmetics right

Usage no npm install needed!

<script type="module">
  import arith from '';




You have probably seen this example a thousand times, you do something like 0.1 + 0.2 and you get 0.30000000000000004. This is because some numbers can’t be accurately represented by JavaScript’s only number type (IEEE 754 Binary Floating-Point). This obviously leads to a lot of headache for us developers. So this is an attempt to cure that. arith is very small (only ~1500 bytes, minified) and it only has four methods; add, divide, multiply and subtract in two flavours.

arith can be used with Node or in the browser (exported as a global variable).

Examples using static methods


arith.add(5, 10); // => 15 


arith.divide(6, 2); // => 3 


arith.multiply(2, 3, 4); // => 24 


arith.subtract(15, 10); // => 5

You can also pass in strings

arith.add('2', '3'); // => 5

Or even an array!

arith.add([2, 3, 4]); // => 9

Examples using instance methods

The difference here is that you can chain multiple operations together. To get the result, you need to call the .value()-method.

Simple addition

arith(5).add(10).value(); // => 15

Chain multiple operations together

arith(10).add(10).subtract(5).value(); // => 15 

Just like the static methods, you can also pass in multiple arguments

arith(1).add(2, 3, 4).value(); // => 10 

They also except strings

arith('1').add('2').value(); // => 3 

Or an array

arith(1).add([2, 3, 4]).value(); // => 10

Comments / Bugs / Ideas

Comments, ideas and bug reports are much appreciated! Please enter them on the issues page. Thanks!