# Question d5112

Aug 27, 2017

$99.3$

#### Explanation:

The thing to remember here is that when dealing with addition or subtraction, the result must have the same number of decimal places as the measurement with the least number of decimal places.

• $27.1 \text{ " -> " " "1 decimal place: } .1$
• $34.538 \text{ " -> " " "3 decimal places: } .538$
• $37.68 \text{ " -> " " "2 decimal places: } .68$

This means that when you're adding these numbers, you must round the answer to $1$ decimal place because that's the least number of decimal places out of the three measurements.

$27.1 + 34.538 + 37.68 = 99.318$

Now, in order to round this number to $1$ decimal place, you must look at the figure that's in the hundredths place

color(blue)(color(black)(99.3)1color(black)(8)#

and compare it to $\textcolor{red}{5}$. If this figure is $\ge \textcolor{red}{5}$, you must add $1$ to the figure that is in the tenths place and get rid of the rest of the decimals.

On the other hand, if this figure is $< \textcolor{red}{5}$, you will leave the figure that is in the tenths place unchanged and get rid of the rest of the decimals.

$\textcolor{b l u e}{1} < \textcolor{red}{5}$

which means that you must leave the figure that is in the tenths place unchanged and get rid of the rest of the decimals.

$99.3 \textcolor{red}{\cancel{\textcolor{b l a c k}{\textcolor{b l u e}{1} 8}}}$

Therefore, you can say that you have

$27.1 + 34.538 + 37.68 = 99.3$

The answer is rounded to one decimal place.