1、 34×36的速算方法:
=(35-1)(35+1)
=35 x 35 -1
=1225 -1
=1224 35x35=3x(3+1)x100+5x5=1225
2、34×36的速算方法:
=(30+4)(30+6)
=(30+4)x30+(30+4)x6
=900+120+180+24
=900+(120+180)+24
=900+300+24
=1224
3、34×36的速算方法:
=(40-6)(40-4)
=(40-6)x40-(40-6)x4
=1600-240-160+24
=1600-(240+160)+24
=1600-400+24
=1224