1. $27 + 38 + 73 = $
答案
138
解析
27+38+73=27+73+38=100+38=138
2. $8.8 + 7.36 + 1.2 = $
答案
17.36
解析
8.8+1.2+7.36=10+7.36=17.36
3. $\frac{7}{15} + (\frac{5}{8} + \frac{8}{15}) = $
答案
$1\frac{5}{8}$
解析
$\frac{7}{15} + (\frac{5}{8} + \frac{8}{15})$
$=\frac{7}{15} + \frac{8}{15} + \frac{5}{8}$
$=1 + \frac{5}{8}$
$=1\frac{5}{8}$
$=\frac{7}{15} + \frac{8}{15} + \frac{5}{8}$
$=1 + \frac{5}{8}$
$=1\frac{5}{8}$
4. $128 + 96 - 28 = $
答案
196
解析
128 - 28 + 96 = 100 + 96 = 196
5. $1000 - 78 - 22 = $
答案
900
解析
1000 - 78 - 22 = 1000 - (78 + 22) = 1000 - 100 = 900
6. $\frac{9}{17} - \frac{2}{5} + \frac{8}{17} = $
答案
$\frac{3}{5}$
解析
$\frac{9}{17} + \frac{8}{17} - \frac{2}{5} = 1 - \frac{2}{5} = \frac{3}{5}$
7. $775 + 187 + 25 = $
答案
987
解析
775+187+25
=775+25+187
=800+187
=987
=775+25+187
=800+187
=987
8. $135 + 39 + 65 + 61 = $
答案
300
解析
135+39+65+61=(135+65)+(39+61)=200+100=300
9. $52.12 - (2.12 + 30.33) = $
答案
19.67
解析
52.12 - (2.12 + 30.33)
= 52.12 - 2.12 - 30.33
= 50 - 30.33
= 19.67
= 52.12 - 2.12 - 30.33
= 50 - 30.33
= 19.67
10. $15 - \frac{7}{23} - \frac{16}{23} = $
答案
14
解析
$15 - \frac{7}{23} - \frac{16}{23} = 15 - (\frac{7}{23} + \frac{16}{23}) = 15 - 1 = 14$
11. $1078 + 676 - 78$
答案
1676
解析
1078 - 78 + 676
= 1000 + 676
= 1676
= 1000 + 676
= 1676
12. $996 + 178 + 4$
答案
1178
解析
996+178+4
=996+4+178
=1000+178
=1178
=996+4+178
=1000+178
=1178
13. $\frac{3}{35} + \frac{5}{16} + \frac{11}{16}$
答案
$1\frac{3}{35}$
解析
$\frac{3}{35} + \frac{5}{16} + \frac{11}{16}$
$=\frac{3}{35} + (\frac{5}{16} + \frac{11}{16})$
$=\frac{3}{35} + 1$
$=1\frac{3}{35}$
$=\frac{3}{35} + (\frac{5}{16} + \frac{11}{16})$
$=\frac{3}{35} + 1$
$=1\frac{3}{35}$
14. $36.64 + 98.8 + 63.36$
答案
198.8
解析
36.64 + 63.36 + 98.8 = 100 + 98.8 = 198.8
15. $2 - \frac{15}{19} - \frac{4}{19} + 38$
答案
39
解析
$2 + 38 - \left( \frac{15}{19} + \frac{4}{19} \right)$
$= 40 - \frac{19}{19}$
$= 40 - 1$
$= 39$
$= 40 - \frac{19}{19}$
$= 40 - 1$
$= 39$
16. $2.25 + 635 - 125\% + 65$
答案
701
解析
2.25 + 635 - 1.25 + 65
=(2.25 - 1.25) + (635 + 65)
=1 + 700
=701
=(2.25 - 1.25) + (635 + 65)
=1 + 700
=701
17. $39.175 - (9.175 + 8.2)$
答案
21.8
解析
$39.175 - (9.175 + 8.2)$
$= 39.175 - 9.175 - 8.2$
$= 30 - 8.2$
$= 21.8$
$= 39.175 - 9.175 - 8.2$
$= 30 - 8.2$
$= 21.8$
18. $5.6 + 1.125 - 4\frac{3}{5} + 7\frac{7}{8}$
答案
10
解析
$5.6 + 1.125 - 4\frac{3}{5} + 7\frac{7}{8}$
$=5.6 - 4.6 + 1.125 + 7.875$
$=(5.6 - 4.6) + (1.125 + 7.875)$
$=1 + 9$
$=10$
$=5.6 - 4.6 + 1.125 + 7.875$
$=(5.6 - 4.6) + (1.125 + 7.875)$
$=1 + 9$
$=10$
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