As a one-liner, I thought of it more as a trick rather than a script.
#!/bin/sh
echo '$*'|awk '{print "'$*'="'$*'}'
tc@box:~$ awkcalc 2^10
2^10=1024
tc@box:~$ awkcalc 2**10
2**10=1024
tc@box:~$ awkcalc 2*10
2*10=20
tc@box:~$ awkcalc '(1+1/2^20)^(2^20)'
(1+1/2^20)^(2^20)=2.71828
Note the quotations in that last call.