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[ Peast arvutamine ]

Ülesanded

Peastarvutamise erivõtted

Näited:

1. 9 ^. 140 = 9 ^. (100 + 40) = 9 ^. 100 + 9 ^. 4 = 1 260
   
2. 24 ^. 11 = 24 ^. (10 + 1) = 24 ^. 10 + 24 ^. 1 = 264
   
3. 16 ^. 8 = 16 ^. (10 – 2) = 16 ^. 10 – 16 ^. 2 = 128
   
4. 17 ^. 101 = 17 ^. (100 + 1) = 17 ^. 100 + 17 ^. 1 = 1 717
   
5. 5 ^. 99 = 5 ^. (100 – 1) = 5 ^. 100 – 5 ^. 1 = 495

1. Korruta arvu 11-ga.

Näide: 25 ^. 11 = 25 ^. 10 + 25 ^. 1 = 250 + 25 = 275

1. 31 ^. 11 = ^. 10 + ^. 1 = + =
2. 44 ^. 11 = ^. 10 + ^. 1 = + =
3. 57 ^. 11 = ^. 10 + ^. 1 = + =
4. 42 ^. 11 = ^. 10 + ^. 1 = + =
5. 65 ^. 11 = + =
6. 39 ^. 11 = + =
7. 19 ^. 11 = + =
8. 73 ^. 11 = + =
9. 49 ^. 11 = + =
10. 15 ^. 11 = + =
11. 28 ^. 11 = + =
12. 97 ^. 11 = + =

Mida paned tähele äärmiste ja keskmise arvude kohta vastuses?

2. Korruta 9-ga.

Näide: 15 ^. 9 = 15 ^. 10 – 15 = 150 – 15 = 135

1. 24 ^. 9 = ^. 10 - = - =
   
2. 67 ^. 9 = ^. 10 - = - =
3. 23 ^. 9 = ^. 10 - = - =
4. 35 ^. 9 = ^. 10 - = - =
5. 22 ^. 9 =  - =
6. 42 ^. 9 = - =
7. 48 ^. 9 = - =
8. 32 ^. 9 = - =
9. 63 ^. 9 = - =
10. 17 ^. 9 = - =
11. 79 ^. 9 = - =
12. 21 ^. 9 = - =
     
    

3. Korruta arvu 99-ga.

Näide: 45 ^. 99 = 45 ^. 100 – 45 = 4500 – 45 = 4 455

1. 21 ^. 99 = ^. 100 – = – =
2. 32 ^. 99 = ^. 100 – = – =
3. 14 ^. 99 = ^. 100 – = – =
4. 63 ^. 99 = ^. 100 – = – =
5. 24 ^. 99 = – =
6. 73 ^. 99 = – =
7. 75 ^. 99 = – =
8. 35 ^. 99 = – =
9. 27 ^. 99 = – =
10. 83 ^. 99 = – =
11. 44 ^. 99 = – =
12. 42 ^. 99 = – =