I'm having trouble running exponent operator in a shell script #!/bin/bashclearnumber1=8number2=2sum1=$(( number1 ** number2 ))echo 8 ^ 2 = $sum1it returns expecting primary:  number1 ** number2 I have also tried ^ instead of ** but still it's not printing the desired result, 8^2 returning 64. I must be missing something, I just don't see what. Any hint would be great, thanks.
#!/bin/bash exponent
shell script
You appear to be running the script in the dash shell.The error message that you quote is what dash outputs when it's failing to understand the ** operator (dash doesn't have it).  It's the same error you get if you try to multiply something with nothing:$ echo $(( 2 * ))dash: 14: arithmetic expression: expecting primary:  2 * Make sure that you either execute your script directly (it has the correct #!-line after all), or by explicitly invoking it with bash:$ bash script.sh