Gauss' method for addition relies on the fact that you can 'pair' certain numbers together. Look at the example:
1+2+3+4+5+6+7+8+9+10
We could manually add all these together from left to right but a clever way to think about this is if we add together the ends of the sum (10+1) we get 11. If we then move one in from the ends and add these (2+9) we also get 11. This means that 1+2+...+9+10 is the same as 11+11+...+11+11.
Because each 2 numbers adds to 11 we know the total number of 11's we have to add together is the length of the sum divided by 2. In our case 5 (10 ÷ 2). We need to add 5 lots of 11 to get our answer. This is the same as 11 × 5 which is easily seen to be 55.
(If you add the 10 numbers together on a calculator you'll see 1+2+3+4+5+6+7+8+9+10 = 55) so this method really makes it a lot quicker.
Looking at your sequence, if we pair the ends together we get 401 (400+1) and we multiply this by the length of the sequence divided by 2. In your case, 200 (400 ÷ 2).
So the sum of all the numbers from 1 to 400 must be 401 × 200 = 80,200.
Remember the steps:
1. Pair the ends together and add them
2. Times this number by the length of the sequence halved
Hope this helps.
For this case, what we should know is that a polygon is a geometric figure with n sides that is closed. It is usually the union of straight lines.
On the other hand, in order to find the area of a figure, we need it to be closed.
Therefore, the edges of an area are confined by snap points.
Answer:
FALSE
Answer:
7.49
Step-by-step explanation:
Well first you have to find how much the bike lock cost.
8.75 x 0.2
1.75 = how much 20% of 8.75 is
8.75-1.75
7 = the cost of the bike lock with the 20% markdown
Now you have to find the sales tax.
7 x 0.07
0.49
7 + 0.49
7.49 = total cost with all the stuff
Hopefully this was helpful. There is a shorter method too tho.
The more dvds the more the height incresases
