Tuesday, November 23, 2010

Multiply by two - How to Practice Playing Cards Multiplied

If you want to teach a child to multiply by two, one of the easiest ways is to explain that multiplication by two is simply doubling the number. Instead of showing the child endless multiplication tables and multiplication charts, get out a deck of cards and do the following:

o Remove the Tens, Jacks, Queens and Kings. You won't need them.
o Take a Two of any other suit (say Spades) and place it face up on the table.
o Take the Ace through Nine of any suit (say diamonds). Shuffle them face down.
o Start turning the cards over one by one, and as you do, say what the product of that number, multiplied by two, is.

o It is important to remember not to say to yourself, "Two times (whatever number you are working on) is..." Try to just say the answer. If you have trouble with a problem, like say, two times 9, remember, you are just doubling the number. If you have problems with that, you may want to "skip count" to the number. To "skip count" you just count by twos, and put out a finger for each number you say. So you'd say "two" and put out one finger. Then you'd say "four" and put out another one. By the time you have nine fingers out, you should be up to "eighteen." That is two times nine.

This is important: Whenever you come to a problem that you don't immediately know the answer to (like if you have to think about it, or skip count to it), you may think you now know the answer because you understand. Do not fall into this trap! This is what hurts many more students. You must know the answer to simple multiplication in the bone. So if you have something like twice and nine were able to skip count, stop, look at the cards is the problem, and call out "2 times 9 in 18" "9 times 2 is 18" "18 is 2 x 9 "18 is 9 x 2", "2 times 9 is 18 years." Saying that, according to hesitate at all to answer. It will surely help you for next time. Youwon't have to do this often until you will instantly recognize that two times nine is eighteen, any time you see it. After you have gone through all nine cards, it's time to do some serious practicing.

o Leaving the Two of Spades face up on the table, take the rest of the cards, except for the Tens, Jacks, Queens and Kings, and shuffle them face down.

o Start turning over cards as before, saying their products. Don't forget to do , stop, look at the cards, see the problem, and say the combinations of the answers out loud, as above

o Keep this up until you can go through all of the cards (there will be 35 of them) in less than one minute. This will not take much practice, and you'll feel great about yourself when you can do it in under a minute. Learning this way has huge advantages. Once you are great at multiplying by two, try it with three. This method also has the advantage that you don't have to print out worksheets, and you can carry a deck of cards anywhere. You also will improve your powers of concentration when you learn like this. I have been diagnosed with ADD, and this method worked wonders for me.

Please keep in mind that we are only talking about whole numbers here. "Simply doubling" is not the definition of multiplication by two. There are subtleties involved that are beyond the scope of this article. But in order to learn simple multiplication by two, this method is much preferable to the "multiplication tables." If the above seems a little complicated, it really isn't.

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