俾奧數題目`` (好簡單-20分!!)

1. 1999+199.9+19.99+1.999
2. 6.4+5.9+6.3+6.1+5.7+5.8
3. 16x6.5
4. 4.44x0.25
5. 56.8x0.125
6. 0.125x0.25x32
7. 16x4.5
8. 0.25x1.25x22.4
9. 0.9+0.99+0.999+0.9999+0.99999








1. 1999+199.9+19.99+1.999
= 2000 - 1 + 200 - 0.1 + 20 - 0.01 + 2 - 0.001
= 2222 - 1.111
= 2220.889

2. 6.4+5.9+6.3+6.1+5.7+5.8
= 6.4 + 5.8 + 5.9 + 6.1 + 6.3 + 5.7
= 12.2 + 12 + 12
= 36.2

3. 16x6.5
= 16x6 + 16x 0.5
= 96 + 8
= 104

4. 4.44x0.25
= 4/4 + 0.4/4 + 0.04/4
= 1.11

5. 56.8x0.125
= 56 * 0.125 + 0.8 * 0.125
= 7.1

6. 0.125x0.25x32
= 0.125 x 8
= 1

7. 16x4.5
= 16*5 - 16*0.5
= 80 - 8
= 72

8. 0.25x1.25x22.4
= 0.25*(22.4 + 22.4 * 0.25)
= 0.25*(22.4 + 22 * 0.25 + 0.4 * 0.25)
= 0.25*(22.4 + 5.5 + 0.1)
= 0.25*28
= 7

9. 0.9+0.99+0.999+0.9999+0.99999
= 1 + 1 + 1 + 1 + 1 - 0.1 - 0.01 - 0.001 - 0.0001 - 0.00001
= 5 - 0.11111
= 4.88889

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巧算
Q:
1. 387+169
2. 284+179
3. 3.48-1.79
4. 2273-655-348
5. 347+357+352+349
6. 7.48+3.19+1.12+6.81
7. 16.28+5.395-1.18-4.305
8. 1992+1993+1994+1995+1996
9. 887+888+889+997+998+999
10.33333x66666
11.7374+6753+2626+2547
12.4.55+6.53+8.92
13.252.5+176.2+424.7+348.3
14.576+204-75+196-125-176
15.100+99+98-97-96-95+......+10+9+8-7-6-5+4+3+2-1
16.132476x111
17.0.6x1.6+0.6x26.4
18.53x46+71x54+82x54
19.4.25x5.24+1.52x2.51
20.2730-276-824
21.38.32-(4.7.2.68)
22.44.8+16.4-24.7-21.7
23.7.9x25+33x2.5
A.
1.556
2. 463
3. 1.69
4. 1270
5. 1406
6. 18.6
7. 16.19
8. 9970
9. 2658
10.22221777778解:33333x66666=66666x6x22222=99999x22222x(100000-1)22222=2222200000-22222=22221777778
11.19300
12.20
13.1201.7
14.600
15.152
16.14704836
17.16.8
18.10700
19.26.0852
20.1630
21.36.3
22.14.8
23.280

還有超級多，再要call我!!!!!

56.8x0.125
0.9+0.99+0.999+0.9999+0.99999
0.25x1.25x22.4
0.125x0.25x32

1.把下列各題中,能把括號字整除的圈起來.
1) [4] 156 388 12382 9898812 56230
2) [3] 726 13137 234276 1238748 9876543421
3) [8] 12312 12356 9453890 12317878 123187362
4) [9] 32523 822573 1238989 23530934 141174190234
5) [6] 21036 351126 8284422 495689450 34538537912
6 [7] 11234496 85005258 54569582 281966872 345358787801
7 [11] 1236719 386364 6877684 11002189 645638805647
8 [13] 11381305 83758378 128108812 983533577 12816063000

答案:
1.156,388,9898812
2.726,13137,234276,1238748
3.12312
4.822573
5.21036,351126,8284422
6.11234496,64569582
7.1236719,386364,6877684,11002189,545638805647
8.1138105,128108812,9835333577,12816063000

2.利用巧算的方法計算下列各題:
1. 1364+972+636+28
2. 513-56-44
3. 7967-498
4. 395+147-195
5. 365+278+135-199
6. 236+664+356+644
7. 751+1287+249+233
8. 589+767+411+233
9. 472+767+528-79
10. 6006-3546+994-454
11. 769-153-269-147
12. 8841-2038+589
13. 1200-447-553
14. 5670-289+589
15. 3296-1999+296-96
16. 9+99+999+9999+99999+999999+9999999
17. 46.6+199.6+4999.6+49999.6+499999.6
18. (1+3+5+7......+2001)-(2+4+6+8......+1998+2000)
19. 102+99+101+95+100+106+97+96+102+103
20. 64+589+26+11+236
21. 1158+5072+6572+4428+1928
22. (576-287)+(487-176)
23. 9+98+997+9996+99995
24. (642-513)+(324-143)+(913-124)
25. 240+241+239+247+236+242+244+233+238+246
26. 49+51+51+58+45+47+51+57+54+55+50
27. 1023+964+1032+1013+987+999+977+968+1001+1036

答案:
1.3000
2.413
3.7469
4.347
5.579
6.1900
7.3000
8.2000
9.1100
10.3000
11.200
12.3000
13.200
14.5970
15.1497
16.0
17.11111103
18.555548
19.1001
20.1001
21.926
22.19158
23.600
24.111095
25.1101

If we multiply together all add primes less than 100,what will be the unit digit of the result???