It works like a phone calculator. 100 + 18% adds 18% of 100, giving 118. For 5000 × 12%, pressing % first turns 12 into 0.12, and = then gives 600.

Yes. Multiplication and division come first, then addition and subtraction. So 2 + 3 × 4 gives 14, not 20.

M+ adds the number on screen to memory and M− subtracts it. Press MRC once to see the memory, and twice in a row to clear it.

Yes. Type digits and + − * /, press Enter for the answer, Backspace to delete the last digit and Esc to clear everything.