Consider the following equation:0.0136 g + 2.70 × 10-4 g - 4.21 × 10-3 g = ? How many digits to the right of the decimal point should be used to report the result? =2, Choose the correct answer=9.66 × 10^-3 g, Which metric unit would be the best choice to report the result?=mg
Answer:
You should use 5 digits to the right of the decimal point.
Explanation:
To be precise in the mathematical operation you have to conserve all significant digits .
Replace the scientific notation for its equivalent in decimal notation:
2.70 x 10-4 g = 0.00027 g
4.21 x 10-3 g = 0.00421 g
Then, compute the addition and subtraction :
0.01360 g
+
0.00027 g
-
0.00421 g
-------------
0.00966 g = 9.66 x 10-3 g
That means you should use 5 digits to the right of the decimal point, which are the biggest amount of digits necessary to represent 2 of the numbers involved in the mathematical operation.
