calculate the value of 1-2+3-4+5-6+7-8+9-10
Answers
Answer:
YOU CAN CALCULATE QUICKLY BY THIS METHOD BUT THE SAFER SIDE IS TO CALCULATE INTERMEDIATELY.⤵️
FAST BUT CAN BE DANGEROUS OPTION:
So we have 1+2+3+4+5+6+7+8+9+10
You first add the smallest number with the greatest. So in this case 1+10= 11
Then you divide that total by 2. So in this case 11÷2= 5.5
Then what you do is simply multiply that number with the greatest number in the selection. So in this case 5.5×10= 55
Answer is 55
(This method is very limited, as the chance that you would get a question that sets out numbers consecutively is unlikely).
Hypothetically speaking: a question could seem to have consecutive addition from 1 to 70. Most people would assume that the pattern of constant addition recurs until the very end, but the question may have a multiply hidden in it somewhere. That's why this can be dangerous even if you do come across a seemingly consecutive addition question.
SAFE BUT SLOWER OPTION:
From 1 to 9 there are (4 × 10) + 5 + 10
This makes = 55
Let me explain:
Each number from 1 to 9 in that list add up with each other to make a ten. So you can use that to your advantage.
So let's start with:
1+9=10
2+8=10
3+7=10
4+6=10.
3. You only have a 5 and a 10 on their own so that is added over the total of tens which is 40.
4. So it comes down to a little breakdown procedure and comes to a more simple 40+15 which is 55.
(This is the safer option that is more sustainable throughout all types of addition problems as it gets you into the mindset of breaking the question apart and then gluing it back together to get the total answer. Even if a multiply is hidden in this question, you would most likely see it and change your method accordingly).
Breaking down a question/problem eliminates the habit of assuming (as breaking down a question has careful observation in of itself), which further prevents silly mistakes.
THIS IS FOR SOMEONE THAT IS LEARNING ELEMENTARY/PRIMARY LEVEL MATHS.⤵️
1+2 = 3
3+4 = 7
5+6 = 11
7+8 = 15
9+10 = 19
So…
add the totals up together and get the grand total.
You can do this by counting each total number by finger and arrive at the final number. (Easier but takes more time)
Or use adding up chart technique. (slightly more difficult but quicker)
Answer:
Step-by-step explanation:
= 1-2+3-4+5 -6+7-8+9-10
= -1 -1 -1 -1 -1
= -5