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#