1994.5*79+0.24*790+244.9：
问题描述：
1994.5*79+0.24*790+244.9
：
答
158000
答
等于158000
答
原式=1994.5*79+2.4*79+3.1*79=（1994.5+2.4+3.1）*79=2000*79=158000
答
79*（1994.5+2.4）+244.9=
79*1996.9+244.9
答
原式=1994.2*79+2.4*79+3.1*79
=（1994.2+2.4+3.1）*79
=2000*79
=2000*80-2000
=160000-2000
=158000
答
=19945*7.9+24*7.9+31*7.9
=7.9(19945+24+31)
=7.9*20000
=158000