Question

Find the value of the 12.9 g - 7.05 g

Answer 1

Answer:

this is the value of 18.7g

Answer 2

Answer:

The value of the 12.9 g - 7.05 g is 5.8 g

Step-by-step explanation:

Given to find the difference between 12.9 g and 7.05 g

The difference is

$12.9 \\~~\underline{~7.05~}\\~~~5.85$

The result of the difference is 5.85 g

To round off the decimals in the result, need to follow the rounding off rules.

• In case of addition or subtraction, the number of decimal places i.e., the number of digits on the right side of the decimal are taken into consideration.
• Identify the quantity having the smallest number of decimal places, and this number gives the number of decimal places to be in the result.

In the given numbers, 1 is the least number of decimal place in 12.9.  So, the result also should be corrected to 1 decimal place.

To correct it to significant figures, the non-significant digit in the result is 5 is to be dropped

To do that following the rules of significant figures.

• If the first non-significant digit is 5, the least significant digit can either be incremented or left unaltered.

• If the last significant figure is odd, increase by one, and if the last significant digit is even, keep it unaltered.

In our case, there is 8 before 5, so simply drop 5 from the result.

Therefore, the value of the 12.9 g - 7.05 g is 5.8 g