86年學力測驗考題 相關單元：2-1-6

將3100以科學記號表示: 3100=a´10m, 其中1£a<10, m為整數, 則a的整數部份為______
                                                                                                                          解答：5

<Sol.>

3100 =
       =10100´log3
       »10100´0.4771
       =1047.71
           =100.71´1047
1=100<100.6990<100.7100<100.7781<101=10  E見註
5=10log5<100.71<10log6=6
100.71=5.…
[註]log5=log()=1-log2=1-0.3010=0.6990
       log6=log(2´3)=log2+log3=0.3010+0.4771=0.7781