Caption:
Text: > # case 1 1+2
> 2+2 2*3 2/5
[1] 4
[1] 6
[1] 0.4
> # case 2
> 8/2-2*(2-3)
[1] 6
> # case 3
> 3*5 *4 /2
[1] 30
>