1+2+3+4+5++100= ?
The sum of 100 consecutive interger from 1 to 100

5050

Step-by-step explanation:

Ace here!

So, you could go through and add up everything but that takes a while, and there's a much easier way to do this. Let's write a rough sample of the numbers.

1, 2, 3, 4, 596, 97, 98, 99, 100.

Now, let's look at these numbers. Notice how if we add the two numbers on the leftmost and the rightmost, we get 101 (1+100). Now, we do 1 from the left added on to one from the right, and get 101(2+99). Then, we can follow that pattern and do 3+98=101, 4+97=101, and as long as we follow that pattern, we keep getting 101 as our answer.

Now, if we keep going with this, eventually we will get to 48+53, 49+52, 50+51.

If we supposedly counted all these pairs, we would find we have 50 pairs. But a quick way to check is to just divide 100 by 2 (100/2) and we get 50.

Now, we have 50 pairs that add up to 101. So, that would be 101 added to itself 50 times, which is just multiplication. 101 × 50 which is 5050.

I hope this helped. Let me know if you have any questions.