Question

Как быстрее сосчитать сумму: 1+2+3+4+5+6+7+8+9?

Answer 1

1+9 2+8 3+7 4+6 это будет 40 и +5 равно 45

Answer 2

Calculating the Sum of 1 to 9

To calculate the sum of the numbers from 1 to 9, you can use the formula for the sum of an arithmetic series. The formula is:

Sum = (n/2) * (first number + last number)

In this case, the first number is 1, the last number is 9, and there are 9 total numbers in the series.

Using the formula: Sum = (9/2) * (1 + 9) Sum = 4.5 * 10 Sum = 45

So, the sum of the numbers from 1 to 9 is 45.