11
11, . , , , .
:
4511
4+5=9. 495.
7611
7+6=13. , 836.
:
10a+b. 11. 110a+11b = 100a +10 (a+b) +b
5 25
5, 2 10. 5, 2 10.
, / 25 / 4 / 100
:
365
36 2, 18. 18 10 180.
3/5
3 2 6. 6 10 0,6
45/25
45 4, 180. 180 100, 1,8
8425
84 4, 21. 21 100 2100.
:
5=10/2, / 2 / 2 10.
, 5
, , , , 25.
:
652
6 7, 42. 25, 4225.
1152
11 12, 132. 25, 13225.
:
10n+5. (10n+5)2 = 100n2+100n+25 = 100n(n+1)+25, .
,
.
:
192 = (20-1)2 = 40040+1=361
422 = (40+2)2 = 1600+160+4 = 1764
:
: (a+b)2 = a2+2ab+b2
: (a-b)2 = a22ab+b2
, , ( ) .
:
1000-725 = (9-7)(9-2)(10-5) = 275
100000 1237 = 100000 01237 = (9-0)(9-1)(9-2)(9-3)(10-7) = 98763
:
.
,
, 9 (8, 7, 6 ..), 1 (2, 3, 4 ..)
:
125+999 = 1125-1 = 1123
6528+996 =7258-4=7254
:
k- 999 = 100..00 1
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4 8
4 : 4, 4.
, , , 10 2 4. : 4, 4.
8. , , .
:
1324: 4+2*2=8 4. 4+2*2+3*4=20 8
6328: 8+2*2=12 4. 8+2*2+3*4=24 8
1. . , . .
. .
. , - .
1.1. , .
1.2. , , .
1.3. , .
1.1. . ( ) , , () .
: ) 164 + 48 = (164 + (48 + 2)) - 2 = (164 + 50) 2 = 214 - 2 = 212;
) 784 + 297 = (784 + (297 + 3)) - 3 = (784 + 300) - 3 = 1084 - 3 = 1081;
) 89 + 433 = 433 +89 = (430 + 90) + 3 - 1 = 520 + 2 = 522.
1.2. . , . , , - , .
: ) 32 +26 +73 +45 = (30 + 20 + 70 +40) + (2 +6 +3 +5) = 160 + 16 = 176;
) 132 + 765 + 423 + 249 =(100 + 700 + 400 + 200) + (30 + 60 + 20 + 40) + (2+ 5 + 3 + 9) = 1400 + 150 + 19 = 1000 + (400 + 100) + (50 + 10) + 9 = 1000 + 500 + 60 + 9= 1569.
1.3. . .
. 65 + 62 + 61 + 63 + 67 + 64 + + 66 + 60.
, 64, , :
1) : 6 8 = 512, 8 ;
2) ; , , , - : 1 2 3 1 + 3 + 0 + 2 4 = -4;
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|
3) :
512 +(-4) = 512- 4 = 508.
. , , 64, 63, :
1) 63 8 = 504,
2) 2 1 2 + 0 + 4 + 1 + 3 3 = 4,
3) 504 + 4 = 508.
, .
1.4. . , , , , .
: 24 +18 72 + 36 = 6 (4 + 3+12+ 6) = 6 25 = 150.
2. . , , , , .
2.1. , .
2.2. , .
2.3. , .
2.4. , .
.
2.1. . .
: 561 35 = (561 1) (35 1) = 560 34 = 526.
, .
: 3125 198 = (3125 + 2) (198 + 2) = 3127 200 = 3127 (100 + 100) =
= (3127 100) 100 = 3027 100 = 2927.
2.2. . , , .
: 1285 296 = 1285 ((296 + 4) 4) = 1285 (300 - 4) = (1285 300) + 4 =
= 1285 (200 + 100) + 4 = (1085 100) + 4 = 985 + 4 = 989.
2.3. . , , , , .
: ) 724 148 = 4 (181 37) = 4 144 = 2 2 144 = 2 288 = 576;
) 91 35 28 = 7 (13 5 4) = 7 4 = 28.
3. . .
. .
. , - .
. , .
3.1. , .
3.2. - , , .
3.3. - , .
, .
|
|
3.1. . , .
.
3.1. 4. 4 2.
: 596 4 = (596 2) 2 = (500 2 + 90 2 + 6 2) 2 = (1000 + 180 + 12) 2 =
= 1192 2 = 1000 2 + 100 2 + 90 2 +2 2 = 2000 + 200 + 180 + 4 = 2384.
3.2. 8. 8 2.
: 298 8 = (298 2) 4 = (200 2 + 90 2 + 8 2) 4 = (400 + 180 + 16) 4 =
= 596 4 = (596 2) 2 = 1192 2 = 2384.
3.3. 16. 16 2.
: 149 16 = (149 2) 8 = (100 2 + 40 2 + 9 2) 8 = 298 8 = (298 2) 4 =
= 596 4 = (596 2) 2 = 1192 2 = 2384.
2n (n ≥ 5).
3.2. . , , .
.
3.4. 15 (25, 35, 45). 15 (25, 35, 45), 30 (50, 70, 90).
: ) 32 15 = (32:2) (15 2) = = 16 30 = 480;
) 28 25 = (28:2) (25 2) =14 50 = 700;
) 16 45 = (16:2) (45 2)= 8 90 = 720.
3.3. . , , .
.
3.5. 5. 5, 10 2.
: 237 5 = (237 10): 2 = 2370: 2 = 2000: 2 + 300: 2 + 70: 2 = 1000 + 300 +35 =
= 1335.
3.6. 50. 50, 100 2.
: 139 50 = (139 100):2 = 13900: 2 = 10000: 2 +3000: 2 + 900: 2 =
= 5000 + 1500 + 450 = 6950.
3.7. 500. 500, 1000 2.
: 237 500 = (237 1000): 2 = 237000: 2 = 200000: 2 + 30000: 2 + 7000: 2 =
= 100000 + 15000 + 3500 = = 118500.
5 10" ( > 3).
3.8. 25. 25, 100 4.
: 239 25 = (239 100): 4 = 23900: 4 = (23900: 2): 2 =
= (20000: 2 + 3000: 2 + 900: 2): 2 = (10000 + 1500 + 450): 2 =
= 11950: 2 = 10 000: 2 + 1000: 2 + 900: 2 + 50: 2 = 5000 + 500 + 450 + 25 = 5975.
3.9. 250. 250, 1000 4.
|
|
: 197 250 = (197 1000): 4 = = 197000: 4 = (197000: 2): 2 = 98500: 2 = 49250.
3.10. 2500. 2500, 10 000 4.
: 182 2500 = (182 10 000): 4 = 1 820000: 4 = (1820000: 2): 2 = 910 000: 2 =
= 455000.
25 10n (n ≥ 3).
3.11. 129. 125, 1000 8.
: 386 125 = (386 1000): 8 = 386000: 8 = (386000: 2): 4 = 193000: 4 =
= (193000: 2): 2 = 96500: 2 = 48750.
3.12. 1250. 1250, 10 000 8.
: 824 1250 = (824 10 000): 8 = 8240000: 8 = (8240000: 2): 4 = (4120000: 2): 2 =
= 2060000: 2 = 1030000.
125 10" (>2).
3.3 75.
3.13. 75. 75, 4, 3 100.
: 408 75 = (408: 4) 3 100 = 102 3 100 = 306 100 = 30600.
55.
3.14. 55. 55, , , .
: 368 55, :
1) 2: 368: 2 = 184;
2) : 18400;
3) : 1840;
4) , : 368 55 = 18400 + 1840 = 19240.
3.4. . , , .
.
3.15. 9. 9, .
: 68 9 = 68 10 68 = 680 68 = 612.
3.16. 99. 99, .
: 347 99 = 347 100 347 = 34700 347 = 34353.
9 99.
3.17. 9. 9, , , .
3.18. 99. 99, , , 100 , .
: 246 99 :
1) , :
246 3 = 243;
2) , , 100: 100 46 = 54;
3) : 246 99 = 24354.
3.19. 999. 999, , , 1000 , .
: 4532 999, :
1) , : 4532 - (4 + 1) = 4527;
2) 1000 , : 1000 532 =468;
3) , : 4532 999 = 4 527468.
3.20. 98, 97, 96. 98, 97, 96, , , .
: ) 253 98 = 253 100 2 253 = 25300 506 = 24794;
) 247 97 = 247 100 3 247 = 24700 741 = 23959;
) 128 96 = 128 100 4 128 = 12 800 - 512 = 12288.
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3.21. 998, 997, 996. 998, 997, 996, , , .
: ) 245 998 = 245 1000 245 2 = 245000 490 = 244510;
) 127 997 = 127 1000 127 3 = 127000 3 81 = 126619;
) 836 996 = 836 1000 996 4 = 836000 3344 = 832656.
3.5. , . , , .
.
3.22. 11. 11, 10 .
: 63 11 = 63 10 + 63 = 630 + 63 = 693.
3.23. 101. 101, 100 .
: 124 101 = 124 100 + 124 = 12400 + 124 = 12524.
3.24. 1001. 1001, 1000 .
: 7639 1001= 7639 1000 + 7639 = 7639000 + 7639=7646639.
10n + 1 (n ≥ 3).
. 11, 101,99.
3.25. 11, . , , .
. 42 11 :
1) 4 + 2 = 6;
2) 42, 6, : 42 - 11 = 462.
. 47 11 :
1) 4 + 7 = 11;
2) 47, 1, 1 (4+1=5), : 47 11 = 517.
3.26. 101, .
: 51 101 = 5151.
3.27. 99, 100.
: 49 99 = 4851.
3.6. , 9 . , 9 , 100, 100.
. 86 97 :
1) 100: 86 3 = 83;
2) 100: (100 86) (100 97) = 14 3 = 42;
3) , : 86 97 = 8342.
3.7. . , , , .
. 16 13 :
1) : 16 +3 = 19;
2) , : 190 + 6 3 = 208.
4. . ( ).
4.1. , .
4.2. () , () .
, , .
4.1. . , .
4.1. 2. 2 .
: 234: 2 = 200: 2 + 30: 2 + 4: 2= 100 + 15 + 2 = 117.
4.2. . , .
.
4.2. 4. 4 2.
: 9824: 4 = 9824: 2: 2 = (9000: 2 + 800: 2 + 20: 2 + 4: 2): 2 = (4500 + 400 + 10 + 2): 2 =
= 4912: 2 = 4000: 2 + 900: 2 + 10: 2 + 2: 2 = 2000 + 450 + 5 + 2 = 2457.
4.3. 8. 8 2.
: 248: 8 = (248: 2): 4 = (124::2): 2 = 62: 2 = 31.
4.4. 16. 16 2.
: 512: 16 = (512: 2): 8 = (256: 2): 4 = (128: 2): 2 = 64: 2 = 32.
2n (n ≥ 5).
4.3. . , , .
.
4.5. 5. 5, 2 10.
: 345: 5 = (345 2): 10 = 690: 10 = 69.
4.6. 50. 50, 2 100.
: 17200: 50 = (17200 2): 100 = 34400: 100 = 344.
4.7. 500. 500, 2 1000.
: 238 000: 500= (238000 2): 1000 = 476000: 1000 = 476.
5 10n (n > 3).
4.8. 25. 25, in 100.
: 41200: 25 = (41200 4): 100 = (41200 2 2): 100 = (82400 2): 100 = 164800: 100 =
= 1648.
4.9. 250. 250, 4 1000.
: 216000: 250 = (216000 4): 1000 = (216000 2 2): 1000 = (432 000 2): 1000 =
= 864000: 1000 = 864.
25 10" ( > 2).
4.10. 125. 125, 8 1000.
: 12000: 125 = (12 000 8): 1000 = ((12 000 2) 4):1000 = (24 000 2) 2: 1000 =
= (48000 2): 1000 = 96 000: 1000 = 96.
4.11. 1250. 1250, 8 10000.
: 24000: 1250 = (24 000 8): 10 000 = (24 000 2) 4): 10000 = ((48000 2) 2): 10000 =
= (96 000 2): 10 000 = 192000: 10000 = 192.
125 10n (n ≥ 2).
4.3 75.
4.12. 75. 75, 3, 4 100.
: 16800: 75 = ((16800: 3) 4): 100 = (5600 4): 100 = 22400: 100 = 224.
, , .
, , , .