The initial example seems broken. In Safari, it looks like 3³ + 4⁴ + 3³ + 5⁵ = 343533+44+33+55=3435 This is apparently because it shows the same example in

The initial example seems broken. In Safari, it looks like 3³ + 4⁴ + 3³ + 5⁵ = 343533+44+33+55=3435 This is apparently because it shows the same example in two different ways in the HTML, the first using MathML (which renders the superscripts), and the second using straight HTML (which doesn't handle the superscripts properly). In Chrome it's broken a bit differently. Here it render as \displaystyle 3^3 + 4^4 + 3^3 + 5^5 = 343533+44+33+55=3435 This is similar to the Safari version except Chrome apparently doesn't support MathML so it renders the annotation instead (\displaystyle 3^3 + …)