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SIMPLE MULTIPLICATION ON THE PYTHABACUS:
Begin teaching simple multiplication with step
counting. Start by speaking a simple verse while walking in the cadence of
an arithmetic counting sequences such as: 1-2,3-4 or 1-2-3,4-5-6. After
the students become familiar with cadence replace the verse with the
counting sequence. You may follow-up this activity with the students
standing in a line counting through a sequence and running under a turning
rope on the appropriate number. I call this activity running under the
rainbow or into the tunnel.
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Continue with a story about
the Hardworking Gnome that
spends his day mining stones. The little gnome takes the same number of
stones from each tunnel he digs. (pic01) In addition to the Hardworking
Gnome, there is a Roly-Poly Gnome that spends all day turning cartwheels and counting all the stones
from the tunnels. The Roly-Poly Gnome can be drawn between two factors
and the multiplication sign can be lifted from the cartwheel posture of
the Roly-Poly Gnome. (pic02) Then tunnels drawn under the multiplication
statement can represent the left side factor and the number of stones
drawn under each tunnel can represent the right side factor.
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After students can represent a multiplication
solution in this way multiplication on the Pythabacus can be introduced.
Reset beads on the frame to the right. Now to solve a problem such as 3 X
4 start at the leftmost bottom bead and count 3 beads to the right. Push
bead 3 to the left until the array touches the left post. (pic04) Then
start at the next bead and count 4 more beads to the right. Push bead 4 to
the left until the array is midway to the left post.(pic05)
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PLACE MOUSE OVER PICTURE FOR ANIMATION
Next, push these 4 beads back to the right against
the array at the right post, leaving a quadrilateral in the middle of the
frame. (pic06)The number of beads composing the quadrilateral is the
solution. Therefore
3 X 4 = 12. The quadrilateral solution can be associated with stones
filling the Hardworking Gnome's mining cart. (pic07)
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It may first appear that on the Pythabacus simple
single digit multiplication is limited to two factors with a sum equal to
or less than the number of beads on the bottom row of the Pythabacus, but
when you run out of beads if you continue counting out your second factor
back at the beginning of the bottom row the solution to any factors can
be found. For the example 9 X 6 the sum of the factors is 15 so it appears
these factors can not be represented, but if after you count out the 9 and
begin counting out the 6 with the remaining 1 bead you continue counting
back at the leftmost bead until you reach 6, the solution can be found. So
reset beads to the left and push 1 bead against the right post (pic11/12).
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Click
here to see Chalkboard Lesson
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PLACE MOUSE OVER PICTURE FOR ANIMATION
Then count five beads starting at the left post to
make 6 with the 1 bead against the right post and push the remaining 4
beads to the right midway to the right post (pic13). Now push the four
beads back to the left a little but not flush against the beads on the
left post, (pic14) leaving the product of 4 X 1, a column of four brown
beads between the 4 and 1. If you count the 5 bottom-row beads remaining
against the left post, each as 10, they will then represent 50. These
bottom roll beads plus the column of 4 now represent the product of 9 X 6
(54).
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