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Question
First guess the answer and then calculate:
77 × 55 = ?
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Solution
On guessing 77 × 55
The numbers will be near to 80 × 50 = 4000
Calculation:
| 70 | 7 | |
| 50 | 70 × 50 | 7 × 50 |
| 3500 | 350 | |
| 2 | 70 × 5 | 7 × 5 |
| 350 | 35 |
By adding the numbers in third and fifth rows you will get
3500 + 350 + 350 + 35 = 4235
Hence, 77 × 55 = 4235.
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| 5. Water paper... | Rs. 4.50/- |
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