## Monday, June 30, 2014

### Car trip license plate game(s)

Courtesy of our friend Ko who introduced it on a school trip:

For times you are stuck driving, especially in the type of dense traffic we have all over Bangkok, you need some games to stay sane and mathematical! There are several you can play, depending on your children:

1. Spot numbers: each person in the car tries to count up using numbers they see outside.  You can play with each as individuals finding their own numbers and the winner is the one who gets the highest number.  Or, as we usually do, play cooperatively where everyone is searching for the next number. I actually liked playing this when we went walking around London as it usually gave us each time to see the number that the other person had found.
2. Simple Addition: one spotter calls out the numbers on a license plate and then there is a race to add them up. Works especially well in Thailand where the numbers are usually of the form: LL[xxxx] where the L's are letters and the x's are digits.  For example, AB 1568 gives you 20 =1+5+6+8.
3. Two digit addition: for slightly older children, break the license plate into two 2-digit numbers, e.g., AB1568 gives you 83 = 15+ 68
4. Four digit addition: another step more difficult. This time, two spotters call out two plates at the same time and then they get added. An example: AB1568 and CD 3458 gives you 5026 (1568 + 3458)
5. Simple multiplication:  spotter calls a license plate and then the players multiply the two smallest numbers, e.g., AB1568 gives 5 = 1x5.
6. Next stage multiplication: multiply the two largest digits. My favourite AB1568 again gives you 48 this time (6x8).
7. After that, if your players are still having fun, try 3 digits, 4 digits, two 2-digit numbers, etc.  Good going if you get up to 2 spotters calling 2 license plates and multiplying the two 4 digit numbers!
If your kids play these a bit, don't be surprised when they start getting the answer before you do! For our part, we've just moved to stage 3.

Isn't this just computation?
Yes, but . . . computation can be fun, too.  Don't force this game (or any other) if they aren't into it. Also, when we play, we spend a lot of the time talking about what we are doing.  Here are some example topics:

• "Wow, how did you calculate that?" (to which the answer will be some amount of reordering, breaking numbers up to form common number bonds, etc)
• "Oh, that is going to be a big one" said when we see a plate with a lot of 8s and 9s
• "Ooh, this is smaller than the last one"
• "This is the same as the last number, but just adding 2"
• "What is the smallest value we could get?"
• "what is the largest we could get?"
• etc
This game helped us survive a long drive on Sunday.  Thanks again, Ko!