Slide 1

! , , . , , . 7 500 . , . 8 000 . 7 500 , 500 .

!8000 7500 = 500

? . =

8 000

- 7 500

= 500 8 000 - (7 500 + 300) = 8 000 7 800 = 200

, , . (500 - 300)

? . =

8 000

- 7 500

= 500 8 000 - (7 500 - 200) = 8 000 7 300 = 700

, . (500 + 200)

!

8 - 3= 5

8 3 ?8 (3 - 1)= (5 +1)8 3 = 58 (3 1) = 8 2 = 6, 5 + 18 3 = 5 , . ... :10 4 = 610 (4 2) = 10 2 = 8 2. 8 - 6 = 2. :a (b x) = (c + x)

8 3 ?

8 (3 + 1)= (5 - 1)8 3 = 58 (3 + 1) = 8 4 = 4, 5 - 18 3 = 5 ... :10 4 = 610 (4 + 2) = 10 6 = 4 2. 6 - 4 = 2. : , .a (b + x) = (c - x)

250, ?2. , 400? 250. (b + 250) = (c - 250) 400. (b - 400) = (c + 400)4. b = 4000, :3. :a - (b + 45) =b) a - (b + 100) =a - (b + 45) = 4000 - 45 = 3955b) a - (b + 100) = 4000 100 = 39003 8003 8003 8003 8003 8003 800 800 700 600 500 400 300 . .

30 000 5 000 = 25 00030 000 (5 000 200) = _________________________25 000 + 200 = 25 200:

7 390 1 796 = 5 5947 390 (1 796 + ) = 5 600

= ___________________________ 5 600 - 5 594 = 63 0003 1003 2003 3003 4003 500

: 2 850, _________ ___________. 1 345, ___________ ___________. 2 8501 345 8 750 b = 6 890 8 750 (b 270) =

6 890 + 270 = 7 160 5 624. , 84?: ______________________________________________________________________

: _______________________________________________________________________

5 624 - 84 = 5 540 84.

1. :

2 850, __________________________ ________________________.

1 345, ____________________________ _________________________.

2. 5 624. , 84?

: _________________________________________________________________

: _________________________________________________________________

3. 8 750 b = 6 890

8 750 (b 270) = ____________________________________________________________