. 8
, .
1. 11
, 10 0 - , , 11?
:
( 53):
5_3
:
5_(5+3)_2
, : 582.
, , :
89*11 =
8_(8+9)_9
(8+1)_7_9
9_7_9 = 989 .
98*11 =
9_(9+8)_8
(9+1)_7_8 = 1078
2.
, 5. +1, 25. !
:
25 = (2x (2+1)) & 25
2×3 = 6
625
35 = 3*(3+1)& 25
3×4 = 12
1225
3. 5
5, , , . . , 2 ( , ). , 0 . , 5. :
2682×5 = (2682 / 2) & 5 0
2682 / 2 = 1341 ( , 0)
13410
:
5887×5
2943,5 ( , , 5)
29435
4. 9
, 9, 1 9 9, . , ( 9×3 ), ( 9×3 2), ( 7). 27.
5. 4
, . , 2, 2:
58×4 = (58×2) + (58×2) = (116) + (116) = 232
6.
15% , . 10% ( 10), :
15% 25 = (10% 25) + ((10% 25) / 2)
2.50 + 1.25 = 3.75
7.
, , , :
32×125 , :
16×250 , :
8×500 , :
4×1000 = 4,000
8. 5
5 . , , 2 : 195 / 5
1: 195×2 = 390
2: : 39,0 39.
2978 / 5
1: 2978×2 = 5956
2: 595,6
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