State the number of significant digits and write the following numbers in scientific notion with the correct number of significant digits.

45.7 -> 3 SD 4.57 x 10(1)
80.0 -> 3 SD 8.00 x 10(1)
200 -> 1 SD 2 x 10(2)
0.00073 -> 2 SD 7.3 x 10(-4)
0.0300 -> 3 SD 3.00 x 10(-2)
42.07 -> 4 SD 4.207 x 10(1)
22.0 -> 3 SD 2.20 x 10(1)

Perform the operations and write your answer with the correct number of Significatn digits

11.5 + 2.688 + 22.56 - 12.89 (3 is the least sig digs in this equation: 11.5) = 22.858 = 22.9
How da heck am I supposed to draw fractions on here lol