The keyboard on this calculator has the number of keys reduced to the minimum by the use of only three function keys, including a combined "x÷" key.
Here, pressing "x÷" gives the multiplication function if "+=" is subsequently pressed to give the answer, and gives the division function if "-=" is subsequently pressed to give the answer, so:
4 x÷ 2 += gives the answer 8.
4 x÷ 2 -= gives the answer 2.
Here, pressing "x÷" gives the multiplication function if "+=" is subsequently pressed to give the answer, and gives the division function if "-=" is subsequently pressed to give the answer, so:
4 x÷ 2 += gives the answer 8. 4 x÷ 2 -= gives the answer 2.