《2025年新课程能力培养四年级数学上册北师大版》

直接写得数
$22×30 =$ $20×14 =$ $88×10 =$ $12×40 =$
$12×50 =$ $60×5 =$ $23×10 =$ $31×40 =$
$84÷4 =$ $642÷3 =$ $650÷5 =$ $639÷9 =$
$816÷8 =$ $624÷6 =$ $\frac{1}{5} + \frac{3}{5} =$ $\frac{7}{9} - \frac{4}{9} =$

答案： $22×30 = 660$
$20×14 = 280$
$88×10 = 880$
$12×40 = 480$
$12×50 = 600$
$60×5 = 300$
$23×10 = 230$
$31×40 = 1240$
$84÷4 = 21$
$642÷3 = 214$
$650÷5 = 130$
$639÷9 = 71$
$816÷8 = 102$
$624÷6 = 104$
$\frac{1}{5} + \frac{3}{5} = \frac{4}{5}$
$\frac{7}{9} - \frac{4}{9} = \frac{3}{9} = \frac{1}{3}$