Why math is hard to do digitally
Plain text boxes cannot hold a fraction or a square root. So digital math usually ends in one of two ways: handwriting with a mouse, or an answer that reads like x^2 + 3x - 5 = 0.
The Expression tool typesets as you type, right on the page, and the result stays editable. Exponents and subscripts also work inside ordinary text, so a short answer does not need a separate tool.