“每人前进一小步，社会前进一大步。”这句公益广告语告诉人们（    ）

1.2+0.3 =____       5.4-2.3=____       0.65+0.35 =____    1-0.09 =____

6.85+1.05 =____   4.89-2.7 = ____   10-9.9 =____          3.27+0.73=____

4.2-4 =____           5.1-2.1 =____      4.3 +2.7 =____       5+ 4.4 =____