Question

The sum of all digits in the numbers 44, 45 and 46 is 27 because (4+4)+(4+5)+(4+6)=27. Find the sum of digits in the first 25 counting numbers: 1, 2, 3, …, 25. NEED HELP PLEASE!!!!!!!!!!!!!!!!!!!!

Answer 1

Total um of the digits of the first 25 numbers is 127

Explanation:

Notice that:

The sum of the digits:

0+1+2+3+4+5+6+7+8+9 = 45

Also notice that the addition of:

10+11+12+13+14+15+16+17+18+19=0+1+2+3+4+5+6+7+8+9 + 10*1 = 45 + 10 = 55

And for the last 6 numbers:

20+21+22+23+24+25 = 0+1+2+3+4+5 + 2 * 6 = 15 + 12 = 27

So the total sum of all this is: 45 + 55 +27 = 127