Korean Job Discussion Forums

[Grotto]

Anyone know of where to pick up some fun math exercises for kids with pretty poor math skills?

Aiming for multiplication/division and anything else that might get the juices flowing.

Also I need more puzzles....I have instituted a math riddle every Monday and am running out of ideas.

Riddle one how can you cut a cake into 8 equal peices with only 3 cuts with the knife?

Riddle two arrange the number 1-9 so they add up to 15 regardless of how you add them(use tic tac toe pattern)

riddle three: How can you prove that half of 12=7?(roman numerals)

[Ya-ta Boy]

I don't find my kids to be poor at math. Just the opposite. But I do get mini heart attacks when I'm told something costs W50,000 when it costs W5,000.

I do simple things like divide into teams and have representatives go to the board and do math problems that I dictate. The winner is the one who can say the correct answer first. We start with one and two digit numbers and work our way up to big numbers. I always make sure I throw in some 13/30, 17/70 type numbers.

When they've learned all the different vocabulary for the math processes we start more complicated problems...What is 14 and 8 divided by 3?

And we do word problems. One shirt costs W15,000. How much are 4 shirts?

But I would love to hear some other games and activities to use. I know in 3rd Grade Miss Allen had us play Baseball, but I don't remember the rules.

[denverdeath]

Here are a couple of sites that look okay:

http://www.teach-nology.com/worksheets/math/puzzles/

http://www.edhelper.com/math.htm

You can find some okay books at some of the stores, too.

[Len8]

Here's another site. Some are difficult, but there are some like the one's you have asked for. Find different ways of adding up a given set of numbers to equal the same sum, and so on

http://www.freepuzzles.com/

[Eunoia]

Riddle #1: Cut the cake in half horizontally (i.e. the blade is flat, parallel to the table), then cut it into quarters.

Riddle #2:

4 9 2
3 5 7
8 1 6

Still working on #3.


It's not exactly math, but have you tried Sudoku? www.websudoku.com has millions of puzlzles of varying difficulty that you can print for free.

[cwemory]

I use http://www.eduplace.com/math/. It is mainly textbook support for Houghton Mifflin Math, but it has puzzles and weekly brain teasers (riddles).

[ontheway]

riddle #3:

roman numeral 12 is Xll.

Cut it in half horozontally and you get Vll. vii is 7.

[tomato]

Ask one student to write a number between 1 and 15, show it to the classmates, but don't show it to you.
This might be difficult to get across.
I usually have to go the quick and dirty route by giving the instructions in Korean:

1���� 15���� ���� �߿� ���� �� ���� ũ�� ���ʽÿ�.
������ ����� �������� ������ ������������.

While the student is doing this, write four lists of numbers on the board.
The first list consists of:
1 3 5 7 9 11 13 15

The second list consists of:
2 3 6 7 10 11 14 15

The third list consists of:
4 5 6 7 12 13 14 15

The fourth list consists of:
8 9 10 11 12 13 14 15

Without even looking at the list, ask the students, "Is it on the first list?" "Is it on the second list?" "Is it on the third list?" "Is it on the fourth list?"

For each list for which you get a yes answer, mentally add the top number on the list. For example, if the secret number is on the second and fourth list, mentally add 2+8. The answer is 10.

On another thread, Mithridates said that there are 10 kinds of people, one that understands the binary system and one that doesn't.

So I'm surprised that Mith didn't beat me in suggesting this magic trick.

[shifty]

Mary likes 225 but not 224.

She likes 900 but not 800.

She likes 144 but not 145.

What does she like?

a) 1600 b) 1700

[tomato]

[GROTTO writes 1 2 3 4 5 6 7 8 9 on the board.]

GROTTO: Suzy, what's your favorite one-digit number?
SUZY: 7.
[GROTTO writes 37 X 21 on the board.]
GROTTO: Let's all do Suzy a favor and multiply 37 times 21.
[STUDENTS do as instructed and are surprised to find that the answer is 777.]

GROTTO: Billy, what's your favorite one-digit number?
BILLY: 9.
[GROTTO writes 27 x 37 on the board.]
GROTTO: Let's all do Billy a favor and multiply 27 times 37.
[STUDENTS do as instructed and are surprised to find that the answer is 999.]

The secret to this trick is to mentally multiply the chosen number by 3, write that product as one of the multiplied numbers, and then write 37 as the other multiplied number.
Since 37 x 3 = 111, the answer will always be the chosen number times 111.
If you put 37 on the top sometimes and on the bottom sometimes, the students might be slower in noticing that 37 appears in every problem.

[tomato]

Mary likes 1600.
She only likes squares.

If the OP doesn't mind, I would like to inject a word puzzle:

Fannee Doollee likes Grotto, but she hates Ya-ta Boy, Denverdeath, Len8, Eunoia, Cwemory, Ontheway, Tomato, and Shifty.

Can you diagnose Fannee Doollee's neurosis?
Incidentally, she loves puzzles but she hates problems.

[Grotto]

Thanks to all

[fatpat]

There is nothing fun about maths!

[Kenny Kimchee]

While technically not a math game but a logic game that uses numbers, sudoku is a lot of fun http://www.sudoku.org.uk/ Search the archives on this site and others to get print-outable boards of varying difficulty. It's also a great way for those of us in public schools to while away the hours...

[Hotpants]

This site contains all the classic word and number puzzles:

http://www.brainbashers.com/

This site contains an e-book of an ancient British maths puzzles collection. Some of the terms are outdated, but there are still enough puzzles in there to keep you going until retirement:

http://www.gutenberg.org/files/16713/16713-h/16713-h.htm

Also, a list of links to math puzzle sites - kids included:

http://puzzles.about.com/od/mathpuzzles/