How do you order the following from least to greatest #-11/5, -pi, -2.98, -sqrt7#?

2 Answers
Jan 21, 2017

#-pi, -2.98, -sqrt(7), -11/5#

Explanation:

First, let's convert each term into it's decimal equivalent:

#-11/5 = -2.2#

#-pi = -3.141#

#-2.98 = -2.98#

#-sqrt(7) = -2.646#

We can now order these from least to greates:

#-pi, -2.98, -sqrt(7), -11/5#

Jan 31, 2017

#-pi," "-2.98," "-11/5," "-sqrt7#

Explanation:

The numbers are all in different formats. A nifty way of doing this without a calculator is to square the numbers which will get rid of the square root.

#-11/5" "-pi" "-2.98" "-sqrt7#

Change format and use rounded values

#-(2.5)^2" "-(3.1)^2" "-(2.98)^2" "-(sqrt7)^2" "# which gives

#-6.25" "-9. ....." "-8. ...... " "-7#

From this it is possible to arrange the original numbers in ascending order.

#-pi," "-2.98," "-11/5," "-sqrt7#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We do not need to know the exact values of #-3.1^2 and -2.98^2#

One is slightly less than -3 and the other slightly bigger.
Knowing this is enough to be able to rank them.