Matching output exactly, even whitespace, is often required. Change the program to output an ending newline.

Click on "Develop mode", and change the output statement to output a newline: System.out.println(userNumSquared);. Type 2 in the input box and run. Click on "Submit mode", click "Submit for grading", and observe that now the first test case passes and 1 point was earned. The last two test cases failed, due to a bug, yielding only 1 of 3 possible points. Fix that bug.

Click on "Develop mode", change the program to use * rather than +, and try running with input 2 (output is 4) and 3 (output is now 9, not 6 as before). Click on "Submit mode" again, and click "Submit for grading". Observe that all test cases are passed, and you've earned 3 of 3 points.