口算我能行。*V4D3w+w*F5T0K4@;r:J+{5G/T
700+800=0q(N9d(D0W)W'D5s1p 1300-400=/z4o1I;U:f9`*V4D3w+w*F5T0K4@;r:J+{5G/T
9000-4000=0w1o2R'Z4W7G'^ 1700-600=:v+f+\+L4y6b;w'Q:o/F;K9p*V4D3w+w*F5T0K4@;r:J+{5G/T
300+400=2K,W7h1p 8000-2000=0B2R5[3`0H)|*V4D3w+w*F5T0K4@;r:J+{5G/T
2800-900=;|,P'j;F/j;D9v+f']+w6F2s5v/D'{ 3500+500=;R1b8U+|8N/}*E*V4D3w+w*F5T0K4@;r:J+{5G/T