口算。7-7= 6-3= 7-3= 5-4= 7-4=6-2= 7-2= 6-4= 6-2= 7-2=7-4= 5-4= 7-5= 4-2= 6-4= 5-3=( )-5=2 ( )-3=0 6-( )=23-( )=2 6-( )=4 ( )-1=67-( )=3 ( )-2=4 7-( )=5( )-6=1 ( )-3=4 6-( )=2
500×6÷5
45÷5×3
3×8÷6
口算。 9×6= 7×8= 9×5= 8×4= 9×5+5= 6×3= 6×6= 7×6= 3×8= 8×7―20= 8×6= 7×4= 6×5= 9×4= 6×9+9= 9×2= 8×5= 7×1= 2×6= 7+7+7+7=
口算。 9×3= 9×6= 9×2= 4×9= 9×1= 9×4= 9×9= 5×9= 8×9= 6×9=