# Math Lesson Plan: Chisanbop (Korean counting to 99)

Prerequisite:

1. Knowledge of Tens and Ones  (for example, for 23, the “2” represents “20” and the “3” represents “3 ones”)

Objective:

1. Learn a quick method of adding to 99 with your hands……This really is not that difficult to learn.  My grades 1 and 2 could do it.  Students love to do Chisanbop.

Materials:

1. everyone’s  two hands
2. chart paper showing values of right and left hands:  right fingers =1 each, right thumb =5, left hand fingers = 10, left thumb =50

Method:

1. Tell students that you have a quick game to show them.  It will make their two hands lightning-fast, like a computer.  This game will allow them to add two 2-digit numbers up to 99, without pencil and paper.
2. Have students spread out their fingers and hold them a few inches from their desktops.  Tell them “you just made the number zero. When none of your fingertips touch the desktop, that is zero.  Only when your fingertips touch the desktop, do you create a number. “
3. Have them press their first fingertip, right hand to their desktop.  That’s 1.  Now the second fingertip as well.  That’s 2.  Now their third fingertip too.  That’s 3,  Fourth fingertip too.  That’s 4.  When you want 5, raise all your fingertips off the desk and only put down your right thumb.  That’s 5.  Keep your right thumb down, and put down your first fingertip, right hand as well.  That’s 6.  Add your second fingertip, right hand.  That’s 7.  Add your third fingertip, right hand.  That’s 8.  Add your pinky fingertip, right hand.  That’s 9, when all your fingertips of your right hand are down, that’s 9.  Your right hand CAN ONLY ADD up to 9.
4. When you want 10, lift all the fingertips of your right hand off the desktop.  You need to use the first fingertip of your left hand.  Left hand fingers are all worth 10, and the left thumb is worth 50!!!  So, 10 is first fingertip, left hand touching desktop. Add first fingertip, right hand as well for 11.  Add second fingertip, right hand for 12.  Add third fingertip, right hand for 13.  Add pinky fingertip, right hand for 14.  Lift right fingertips, but leave down first fingertip, left hand, and add right thumb down for 10 + 5 ….now you have 15.  16 is first fingertip, left hand, thumb, right hand, plus first fingertip, right hand.  For 17, add second fingertip, right hand to that.  For 18, add third fingertip, right hand to that.  For 19, add pinky fingertip, right hand, so that all your right hand is touching, as well as your first fingertip, left hand (10 + 5 + 4 = 19)
5. Lift all fingertips off the table now.  For 20, touch first and second fingertips, left hand to the desktop.  For 21, add first fingertip, right hand.  For 22, add second fingertip, right hand…..etc. to 49.
6. For 50, lift all fingertips and touch your left thumb down.  That’s 50.  60 is left thumb down and first fingertip, left hand down.  Rest of left hand fingers down, plus left thumb is 90 (50+10+10+10+10 =90)  For 91, all your left hand is down, plus first fingertip, right hand.  Continue until left hand is all down and right hand is all down.  That’s 99.   Count to 99 a few times to ensure students understand finger values.
7. Ask them to make 37.  Make 17.  Make 55.  Make 63.  If they have trouble, remind them of finger values.  Do it with students.  (I put my back to them and show them how I use my fingers, above my head,  on the blackboard.)  When they can make the numbers, try some questions.
8. Write 39 + 27 on the board.  Ask if anyone knows the answer.  Tell them we’re going to try this new game to add them up, and it will be VERY quick and VERY accurate.
9. Have students make 39 with their fingers…first, second, third fingertips, left hand (30) and all off the right hand (5+1+1+1+1=9).  Now tell students we will be adding 27 to this.  Go on from 39, adding 27, saying 10 and making 49 with your pinky fingertip, left hand, then saying 20 and making 59 with your left thumb down (other left fingertips up) , then saying 21, (adding 1 to the 9 of your right hand makes 10,) so left hand comes up and makes 10 so first fingertip, left hand goes down with left thumb which is already down, 22 (first fingertip, right hand goes down), 23 (second fingertip, right hand down as well), 24 (third fingertip, right hand goes down now too), 25 (four fingertips, right hand are now down), 26 (lift four fingertips, right hand up and put right thumb down), 27 (add first fingertip, right hand down now).
10. Tell the class that this is the answer.  Add it up with them.  50 (left thumb) + 10 (first fingertip, left hand) + 5 (right thumb) +1 (first fingertip, right hand).  Say 50, 60, 65, 66, showing students how you count each value using the appropriate finger or thumb.  The answer is 66.

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