口算:4W0?)c+I.L,I7q/S5P(S-T
25×20=0e1_3^.l-B'w:m6R4W0?)c+I.L,I7q/S5P(S-T
480÷6=;B2n2z;[9[-f/G:b4a(f9v(S']+}4W0?)c+I.L,I7q/S5P(S-T
80×4=(N-P,R-Q;n4W0?)c+I.L,I7q/S5P(S-T
70+60=3J0P9h;C6K.j-t4W0?)c+I.L,I7q/S5P(S-T
450-50=2g)A*C+D)h8y*H4X:d4W0?)c+I.L,I7q/S5P(S-T
102-90=7a2c.|2e/?3`4W0?)c+I.L,I7q/S5P(S-T
50×30=9v;o3J4S4W0?)c+I.L,I7q/S5P(S-T
840÷4=3b9G(z-P:f6{.J'P*I4W0?)c+I.L,I7q/S5P(S-T
89×30≈+S,S+V*Q;o.v4W0?)c+I.L,I7q/S5P(S-T
32×48≈*M'E8x.H1k1u3F;t4W0?)c+I.L,I7q/S5P(S-T