AC Lim's answer to Coral's Primary 6 Maths Data Analysis Singapore question.
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Hope this helps
Date Posted:
1 year ago
Thanks. Can i ask why divide by 2?
Thank you. Can i ask why divide by 2?
Let start with smaller number...
Sum from 1 to 6.
1+2+3+4+5+6=21
So, we pair up the number.
1+6=7
2+5=7
3+4=7
Total = 3×7 = 21
We add 2 numbers together, so ÷2
That's mean, we find how many pair it have for the sum.
For sum from 1 to 198...
198÷2= 99 pairs.
Each pair = 1+198 = 199
Therefore, total = 99×199= 19701.
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Sum from 1 to 6.
1+2+3+4+5+6=21
So, we pair up the number.
1+6=7
2+5=7
3+4=7
Total = 3×7 = 21
We add 2 numbers together, so ÷2
That's mean, we find how many pair it have for the sum.
For sum from 1 to 198...
198÷2= 99 pairs.
Each pair = 1+198 = 199
Therefore, total = 99×199= 19701.
.
.
.
.
Got it! Thank you so much for the clear explanation.
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