To enter a negative exponent, such as 4.9x10-3 then type 4, ., 9, EE, 3, +/-, where +/- is the sign key at the bottom.
A negative number is, such as -5.2x10-8, is entered as 5, ., 2, +/-, EE, 8, +/-.
If the display becomes confused, hit AC for All Clear.
To multiply two numbers, for example, 3.4x104 times 4.2x10-2, you type in the first number, hit 'x', then enter second number, hit the '=' key and the answer should be 1428.
To figure out a cube root, for example, the cube root of 5.77x10-9, then enter the number, then hit the y^x key, then enter 0.333333 (that's 1/3 or cube root) and hit '='. You should get 0.00179.
See the main web page for more math help.