bin(calc): support multiple expression inputs

.config/shell/bin/calc

@@ -1,6 +1,8 @@
 #!/bin/zsh
-# Note: this is compatible with `sh`, but because
-# `sh` does not handle floats, I'm choosing `zsh`.
+# Basic calculator using the shell
+# Note that zsh can handle floating-point math, whereas POSIX sh cannot
 
-# Believe it or not, zsh makes for a fine calculator
-echo $(($*))
+for v; do
+   printf ' %s ' "$(($v))"
+done
+echo