直接写出得数 + = + =

1. (2022五下·云梦期末) 直接写出得数
$\text{[math]}$ + $\text{[math]}$ =       $\text{[math]}$ + $\text{[math]}$ =          $\text{[math]}$ - $\text{[math]}$ =          1- $\text{[math]}$ =

$\text{[math]}$ - $\text{[math]}$ =         2- $\text{[math]}$ =            $\text{[math]}$ + $\text{[math]}$ =          4.4+ $\text{[math]}$ =

2 $\text{[math]}$ + $\text{[math]}$ =        4-1 $\text{[math]}$ =