一、口算。
$5 + 90 =$ $6 + 30 =$ $30 + 10 =$
$90 + 5 =$ $30 + 6 =$ $10 + 30 =$
$95 - 90 =$ $36 - 30 =$ $40 - 10 =$
$95 - 5 =$ $36 - 6 =$ $40 - 30 =$
$20 + 6 =$ $9 + 40 =$ $3 + 20 =$
$37 - 30 =$ $75 - 5 =$ $84 - 4 =$
$80 + 3 =$ $20 + 1 =$ $60 + 8 =$
$65 - 5 =$ $94 - 90 =$ $50 - 20 =$
$7 + 60 =$ $20 + 70 =$ $80 + 4 =$
$50 + 7 =$ $56 - 50 =$ $29 - 9 =$

一、95 36 40 95 36 40 5 6 30 90 30 10 26 49 23 7 70 80 83 21 68 60 4 30 67 90 84 57 6 20

二、连一连。

二、