Proper Decimal Place, Please Help

Express each answer to the proper decimal place.

(0.61 x 10^-6) + (0.11 x 10^-4) + (0.0232 x 10^-3)

My answer: 3.5 x 10^-5

Is my answer correct?

(0.61 x 10^-6) + (0.11 x 10^-4) + (0.0232 x 10^-3)
10^-3 [ 0.61 * 10^-3 + 0.011 + 0.0232 ] =
10^-3 *[0.00061 + 0.011 + 0.0232 =
0.035 * 10^-3 = 3.5 * 10^-5
ur answer is correct

Using Significant Figures the answer would be 3.481x10^-5. If rounding to the nearest 10th of a unit, your answer would be correct.