1.2121212÷3.030303(懷疑此題抄丟一個(gè)零,故加上一個(gè)零)
=1.2*1.010101/3*1.010101
=0.4
3.3+3.33+3.333+3.3333+3.33333
=3*1.1+3*1.11+3*1.111+3*1.1111+3*1.11111
=3*(1.1+1.11+1.111+1.1111+1.11111)
=3*5.5432
1990×198.9-1989×198.8
=1990×198.9-(1990×198.8-198.8)
=1990×198.9-1990×198.8+198.8
=1990×(198.9-198.8)+198.8
=1990*0.1+198.8
=199+198.8
60.7×0.6
=(60+0.7)*0.6
=36+0.42
=36.42
0.45×172-0.9×71×0.5-0.45
=0.45×172-0.45×71-0.45
=0.45*(172-71-1)
=0.45*100
=45
用鍵盤寫算式太費(fèi)勁.有的題沒計(jì)算到最后,計(jì)算到最后的答案也未必對(duì).只是方法和思路應(yīng)該是正確的.時(shí)間匆匆,有不準(zhǔn)確的地方,見諒!