100.2²=(100+0.2)²=100²+2*100*0.2+0.2²=10000+40+0.04=10040.04
98×98=(100-2)²=100²-2*100*2+2²=10000-400+4=9604
37²=(40-3)²=40²-2*40*3+3²=1600-240+9=1369
（20又2/1）²=(20+0.5)²=20²+2*20*0.5+0.5²=400+20+0.25=420.25
2008²=(2000+8)²=2000²+2*2000*8+8²=4000000+32000+64=4032064
(14又4/3)²=(14+0.75)²=14²+2*14*0.75+0.75²=196+21+0.5625=217.5625