来自蒋永忠的问题
2106-297+599145+263+55-19.
2106-297+599
145+263+55-19.
1回答
2020-12-03 07:06
2106-297+599145+263+55-19.
2106-297+599
145+263+55-19.
(1)2106-297+599,
=2100+6-300+3+600-1,
=(2100-300+600)+(6+3-1),
=2400+8,
=2408;
(2)145+263+55-19,
=(145+55)+(263-19),
=200+244,
=444.