25×(18+4)簡便計算
25×(18+4)
=25×(4+4+4+4+2+4)
=25×(4×5+2)
=25×4×5+25×2
=100×5+50
=500+50
=550
為了讓樓主看清楚,寫的囉嗦了點.
二十五分之十八×4+二十五分之二十一×18簡便計算,
=18/25*4+18/25*21
=18/25*(4+21)
=18/25*25
=18
102*0.36簡便計算
=(100+2)×0.36
=100×0.36+2×0.36
=36+0.72
=36.72
36*2.54+1.8*49.2 2004分之2003*2003怎麼簡便計算啊?
*是乘號@
原式= 1.8*50.8+108*49.2
=1.8*(50.8+49.2)
=1.8*100
==180
2004 = 2003+1