小虎买一本《昆虫王国的奥秘》,付给营业员10元,找回2.45元.一本《昆虫王国的奥秘》元?
7.4+2.6= 6.6+2.9= 7.4−4.4= 5.08+3.68=
1.5−0.8= 8.6−6.8= 5.3+3.7= 0.66−0.06=