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
102×7.3÷5.1 17+-7
×3÷×3 25×7×4 34÷4÷1.7 1.25÷×0.8
12.06+5.07+2.9430.34+9.76-10.34
1.3×11.6-1.6×1.3 1--
(48×75×81)÷(24×25×27) 7.5×2.3+1.9×2.5 5-(-) 19.68-(2.97+9.68)