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1. 口算。
$3.6 + 2.4 = $ $2.3 + 1.1 = $ $8.2 + 2.8 = $ $4.5 + 2.6 = $
$3.6 - 2.1 = $ $2.6 - 1.9 = $ $2.9 - 1.4 = $ $3.6 - 2.5 = $
$3.6 + 2.4 = $ $2.3 + 1.1 = $ $8.2 + 2.8 = $ $4.5 + 2.6 = $
$3.6 - 2.1 = $ $2.6 - 1.9 = $ $2.9 - 1.4 = $ $3.6 - 2.5 = $
答案
$3.6 + 2.4 = 6$ $2.3 + 1.1 = 3.4$ $8.2 + 2.8 = 11$ $4.5 + 2.6 = 7.1$
$3.6 - 2.1 = 1.5$ $2.6 - 1.9 = 0.7$ $2.9 - 1.4 = 1.5$ $3.6 - 2.5 = 1.1$
$3.6 - 2.1 = 1.5$ $2.6 - 1.9 = 0.7$ $2.9 - 1.4 = 1.5$ $3.6 - 2.5 = 1.1$
2. 列竖式计算。
$1.2 + 5.6 = $ $3.5 + 10.2 = $ $0.8 + 1.3 = $
$6.8 - 5.3 = $ $13.6 - 3.7 = $ $9.5 - 0.8 = $
$1.2 + 5.6 = $ $3.5 + 10.2 = $ $0.8 + 1.3 = $
$6.8 - 5.3 = $ $13.6 - 3.7 = $ $9.5 - 0.8 = $
答案
$1.2 + 5.6 = 6.8$ $3.5 + 10.2 = 13.7$ $0.8 + 1.3 = 2.1$
$6.8 - 5.3 = 1.5$ $13.6 - 3.7 = 9.9$ $9.5 - 0.8 = 8.7$ 竖式略
$6.8 - 5.3 = 1.5$ $13.6 - 3.7 = 9.9$ $9.5 - 0.8 = 8.7$ 竖式略
1. 
(1)买一条毛巾和一块肥皂要花多少元钱？
(2)一瓶洗发露比一条毛巾贵多少元钱？
(3)请你提出一个数学问题并解答。
(1)买一条毛巾和一块肥皂要花多少元钱？
(2)一瓶洗发露比一条毛巾贵多少元钱？
(3)请你提出一个数学问题并解答。
答案
(1)$8.8 + 3.8 = 12.6$(元)
(2)$22.5 - 8.8 = 13.7$(元)
(3)略
(2)$22.5 - 8.8 = 13.7$(元)
(3)略
2. 一桶油连桶重 17.5 千克,用去油的一半后连桶重 9.9 千克。所有油用完后,桶重多少千克？
答案
$17.5 - 9.9 = 7.6$(千克)
$9.9 - 7.6 = 2.3$(千克)
$9.9 - 7.6 = 2.3$(千克)
