Expressions includes vars and anything else with value
Ex:
1 + 2
“hello”
@sqr 2
To get the result value from expression, you could use assignment:
$value: 1+2+3/3
@echo “value:” $value
> value: 4
You could also get the value of expression in previous command using $?
1+2+3/3
@echo “value:” $?
> value: 4