直接写出得数。 ×4= 1- = × =

1. (2019六上·滕州期中) 直接写出得数。
$\text{[math]}$ ×4=       1- $\text{[math]}$ =       $\text{[math]}$ × $\text{[math]}$ =        $\text{[math]}$ ÷ $\text{[math]}$ ×3=
$\text{[math]}$ ÷ $\text{[math]}$ =        $\text{[math]}$ ×21=      $\text{[math]}$ - $\text{[math]}$ =      4× $\text{[math]}$ ÷4× $\text{[math]}$ =
12× $\text{[math]}$ =          0÷ $\text{[math]}$ =        $\text{[math]}$ × $\text{[math]}$ =     $\text{[math]}$ ÷ $\text{[math]}$ × $\text{[math]}$ =