Pythabacus Lessons

Games And Activities

Pythabacus Simulation

Numerals

Counting

Simple Addition

Simple Subtraction

Simple Multiplication

Short Multiplication

Short Division

SIMPLE SUBTRACTION ON THE PYTHABACUS:

Begin the lesson with a subtraction version of the Duck-Duck-Goose game. With students sitting on the floor in a circle and one student standing say, "There was a little gnome that went mining stones and after breakfast he got seven stones for his sack." The standing student walks around the circle and counts seven students while the teacher remains standing by the first student counted. After the standing student has counted seven students the teacher says, "As the little gnome carried out his stone three fell through a hole in his sack. The standing students counts backwards three sitting students and the teacher asks, "So how many were left upon the little gnomes back." The student can now look back to where the teacher is standing and count all the students between themselves and the teacher to solve the subtraction question.

 

 

When the students are comfortable with this kinesthetic addition, continue the lesson with the same story motivating a fine motor activity using plasticene or flattened marbles to represent the jewels gathered by the little gnome. Give each student or group of students a bag of jewels. Now begin the story and have the students take from their bags the number of stones the little gnome mined before snack and place them upon their desk in a roll. (pic01) Then continue the story and have the students take from the roll of stone, startng on the right the number of stones that fell from the little gnome's sack. (pic02)

 

   

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Simple subtraction on the Pythabacus is demostrated as follows. Reset beads on frame against the right post and push the leftmost bottom bead against the left post. (pic12) Now to solve a problem such as 7 - 5 start your count with the remaining leftmost bead under the triangle and count to the right. First count 7 beads on the bottom row and push these a little toward the left post. (pic13 )

  PLACE MOUSE OVER PICTURE

   

Then start at bead 7 and count 5 bottom beads to the left. Now push the next bottom bead to the left against the left post. (pic14)  At this point you must push the second bead from the left post to the right leaving a diagonal column of beads above the bottom row bead against the left post. (pic15) The number of brown beads above the bottom bead of the column is the solution.

Therefore 7 - 5 = 2.

 

 

The student can now respond to a subtraction statement such as: ? = 7 - 2 by associating the gnome story with a pictorial solution. (pic16) The student would draw 7 stones to represent how many the gnome mined before snack. Then the student would count backward from the right 2 stones to represent how many fell through the hole in the gnome's bag and draw a horizontal line under these 2 with an arrow pointing to the right to indicate they were takenaway . To indicate the

 

solution is how many stones remained in the gnome's sack the 5 stones to the left of the arrow are put in parenthesis.