How do you evaluate 1.7-(-0.8)+4.013?

1 Answer
Mar 4, 2018

1.7−(−0.8)+4.013 equals 6.513

Explanation:

Evaluate
1.7−(−0.8)+4.013

1) Clear the parentheses by distributing the minus sign
1.7+0.8+4.013

2) Now this is like any other addition of decimals problem.
Add the numbers by lining them up according to the decimal points

color(white)(....) 1.7
color(white)(....) 0.8
color(white)(.) + 4.013
------------

3) Sometimes it is easier to add numbers like this if you fill in the blank spaces with zeros

color(white)(....) 1.700
color(white)(....) 0.800
color(white)(.)+  4.013
color(white)(....) ―――
color(white)(....) 6.513 larr answer

color(white)(..............) ――――――

Check

Check by estimating

This problem is almost the same as
2 - (-1) + 4

2 + 1 + 4 =7

The actual answer is close to this estimated sum of 7, so it's probably correct.

Check