Mathlean · Online math workspace
Set union calculator
Combine finite sets while retaining each distinct element once.
How to use this calculator
Edit the two sets around the union symbol. The example gives {1,2,3}.
Tap the math below to edit it and see the result. Once a result is ready, press Tab on a hardware keyboard to accept it. Outside a matrix, Return completes the line; the phone math keyboard has the same Return action.
Try it here
Interactive tools require JavaScript. You can read the guide and example without it.
What to know
Sets are unordered and discard duplicates; use lists when order and repeated observations matter.
Mathlean combines visual mathematical input with computation and canvas tools. Results depend on the expression and available engine support; check important answers independently.