这些题用简便算法谁会?①:[14×15×48]÷[7×3×16] ②33333×66666 ③1997×19981998
3个回答

①:[14×15×48]÷[7×3×16]

=(2*7*3*5*3*16)÷(7*3*16)

=2*5*3=30

②33333×66666

==33333*3*22222

=99999*22222

=(100000-1)*22222

=2222200000-22222

=2222177778

③1997×19981998-1998×19971997 =(1997*1998)*(10001-10001)=0

④[+25]×[-4]=-100

⑤0.25×32×0.125=0.25*4*8*0.125=1*1=1