If John scored 100 on his first 3 tests and an 80 on his 4th, what was his average score across the 4 tests?
100+100+100+80=
<gadget id="calculator">100+100+100+80</gadget>
<output>380</output>
380 total score across 4 tests
380 total score / 4 tests = 
<gadget id="calculator">380/4</gadget>
<output>95</output>
95 average score.

<result>95</result>