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→INVESTIGATION 3: COMMAND SUBSTITUTION / MATH OPERATIONS
'''Perform the Following Steps:'''
# Confirm that you are located in your '''home''' directory in your Matrix account.<br><br>Let's demonstrate that the Unix/Linux shell stores numbers as ascii text <br>which can cause problems when performing math operations.<br><br>
# To demonstrate the need for the '''(( ))''' construct, issue the following Linux command from the shell:<br><span style="color:blue;font-family:courier;font-weight:bold">echo "1 + 2"</span><br><br>What did you notice?<br><br>
# Issue the following Linux commands (using the ''math construct''):<br><span style="color:blue;font-family:courier;font-weight:bold">echo "$((1 + 2))"</span><br><br>What did you notice?<br>The <span style="font-family:courier;font-weight:bold">(( ))</span> construct converted values '''1''' and '''2''' from ''text'' to '''binary numbers'''.<br>The '''$''' in front of the construct '''expands''' the result of the calculation.<br><br>