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Question
primary 5 | Maths
| Whole Numbers
2 Answers Below
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How to do this?
Date Posted: 5 years ago
Views: 355
The trick is to group them this way.
1 + 2 + 3 + ... + 98 + 99 + 100
= (1 + 100) + (2 + 99) + (3 + 98) + ... + (49 + 52) + (50 + 51)
There are a total of 50 brackets with values 101 each.
So total sum is 101 x 50 = 100 x 50 + 1 x 50 = 5000 + 50 = 5050.
1 + 2 + 3 + ... + 98 + 99 + 100
= (1 + 100) + (2 + 99) + (3 + 98) + ... + (49 + 52) + (50 + 51)
There are a total of 50 brackets with values 101 each.
So total sum is 101 x 50 = 100 x 50 + 1 x 50 = 5000 + 50 = 5050.
There is a formula for this based on this method of grouping, but it’s probably too advanced for you as algebraic expressions are required.
THKS!
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Using the formula , S=n(n+1) divide by 2 .N is the last value.
Date Posted:
5 years ago
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Hope this helps
Date Posted:
5 years ago
Yeah it does help THKS for Ur ideas/suggestions!
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