口算。7-3= 6-3= 5-4= 7-2=7-2= 6-2= 7-2= 6-4= 7-4=6-4= 5-4= 7-5= 6-2= 7-7=7-4= 5-3= 6-5= 5-1=7-4= 3-3= 7-5= 7-( )=5 ( )-3=2( )-0=6 6-( )=1 ( )-6=1
3.8×13+8.7×38 [0.85+(9.25+0.65)÷0.2]×20
132-1.05÷10.5+27 [4.75+8.4÷(9.2-6.8)]×40
7.8×36+78×6.4 10.8+6.7-10.8+4.3
86.4÷3.2-6.4×3.2 32.4×O.9+0.1×32.4
168.1÷(4.3×2-0.4) 168.8÷(24.3×2-6.4)