# Math Challenge 2019

Discussion in 'Mathematics' started by Shin0bi3Z, Jul 2, 2019.

1. ### Shin0bi3ZNew commenter

In my head it looks like this:

20 + 40 =60,
60 + 7= 67,
67 + 8= 75

2. ### nervousnedSenior commenter

27+50=77
77-2=75

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3. ### BG54Occasional commenter

Column addition, identical to the way I do the calculation on paper.

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4. ### teselectronicOccasional commenter

30 + 50 - 5 = 75

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40 + 27 = 67
67+8 = 75
or computerwise - convert to binary
11011 + 110000 = 1001011 = 64+8+2+1 = 75
Could have been worse if I used hexadecimal.

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6. ### NoSuchThingAsNormalNew commenter

60 + 15 = 75

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7. ### Shin0bi3ZNew commenter

I like your approach to the problem.

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8. ### Shin0bi3ZNew commenter

That is cool, I never thought of solving it that way. That is illuminating! Great!
You are right hexadecimal is a whole other beast.

9. ### Shin0bi3ZNew commenter

Keeping it simple that is good.

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10. ### Shin0bi3ZNew commenter

Do you start on the right side first or the left side first?

12. ### BG54Occasional commenter

Units first, then tens.

Yup, that's how I did it.

14. ### maths_mikeyNew commenter

Why do three sums when you can do 2? 27+8 =35 35+40=75

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OK got you.

17. ### briceanusNew commenter

Sorry, but this is inefficient and open to error.

addition is simpler than subtraction, 3 operations is quicker than 5. IMO

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18. ### Shin0bi3ZNew commenter

That is a great point, something to think about.

19. ### Shin0bi3ZNew commenter

You prefer efficiency in doing math, well done

20. ### BensusanNew commenter

Left to right.

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