If you need to type an exponent on a chromebook, or any other math symbol, use the Unicode trick. Here are some symbol Unicodes:

Multiplication Symbol: Ctrl+Shift+U then type 00d7 then hit enter

Division Symbol: Ctrl+Shift+U then type 00f7 then hit enter

Exponents (type Ctrl+Shift+U before everything)

Power of 0: 2070+enter

Power of 1: 00b9+enter

Power of 2: 00b2+enter

Power of 3: 00b3+enter

Power of 4: 2074+enter

Power of 5: 2075+enter

Power of 6: 2076+enter

Power of 7: 2077+enter

Power of 8: 2078+enter

Power of 9: 2079+enter

Hope this helps!