This is one of the question for Shane's maths test. Granted, it's only a practice paper prior to his mid-term, but how many eight year olds can answer this question logically? How about you, big brothers and sisters?
Interesting indeed.
I wonder how his year end maths questions will be like.
9 comments:
The fastest method? Add up the numbers from the 2 ends, 9+1=10, 8+2=10, 7+3=10, 6+4=10, then left 5, so there will be 4 of 10s = 40 and then +5 = 45.
1+9=10
2+8=10
3+7=10
4+6=10
Ans=10+10+10+10+5=45
Logically? Heh. By not doing the sum in series of (1+2+3 and so on...) but by understanding the pattern & rearranging them to make an easy element of '10'-s.
So see them as:
1+9
2+8
3+7
4+6
5
Which when added will be: 10+10+10+10+5 = 45.
=)
a_x
it's
9+1=10
2+8=10
3+7=10
4+6=10
+the remaining 5
=45
i miss you angie che che
Fastest way?
Add the 1 (1st digit) to the 9 (last digit) which makes a 10. Strike out the 2 used digit in the process which makes 2 & 8 the 1st and last digit. Add 2 to 8 which makes another 10. Total 20. Repeat these steps till there is a standalone 5 and add that...viola! 45!
1+9=10
2+8=10
3+7=10
4+6=10
then +5
answer = 45
1+9 = 10
2+8 = 10
3+7 = 10
4+6 = 10
total 50
50+5 = 55
besides good at counting $$$$ i never passed my maths but if goes by common sense, the followin method below is the fastest way for me to solve tis sum.
take the first and last number and add it up. den 2nd and 2nd last number and add up so on and so forth.
do i get any prizes if my ans is correct =P
Seems like you peeps love maths lesson eh? Yes, you guys got the answer right except for Anon - Friday, June 5, 2009 1:11:00 PM SGT, but i believe it's a typo mistake :)
Alright, the next time i do this, i make sure i have some gifts to spare. That would be interesting!
Haha...and i'm back from HK :)
Miyuki sweetheart, i miss you very much too!! xxx
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