Question

[Nguyễn Thị Thanh Trúc]

TÍNH NHANH:

a) 135+360+65+40;

b) 463+318+137+22;

c)20+21+22+ ... +29+30

Answer 1

[Lưu Tiến Đạt]

a) 135+360+65+40=[135+65]+[360+40]=200+400=600

b) 463+318+137+22=[463+137]+318+22=500+340=840

c)20+21+22+ 23+24+25+26+27+28+29+30=[20+30]+[21+29]+[22+28]+[23+27]+[24+26]+25=50+50+50+50+50+25=275

                                                                         HỌC TỐT NHÉ BẠN