Subtraction With Strip Board

From Montessori Album
Subtraction With Strip Board
Math - Memory Work
Sub Strip Board 11.JPG
LevelPrimary
Age5+

This activity gives the child practice figuring out and memorizing subtraction facts.

Presentations

Presentation One

  1. Take the material to a mat or table. Lay out as shown.
    Sub Strip Board 1.JPG
  2. The first page should have just one problem: 18-9=
    Take the 9 strip and cover up the numbers starting from the end. The last visible number is the answer.
    Sub Strip Board 2.JPG Sub Strip Board 3.JPG
  3. The next page should have two problems: 17-9= and 17-8=
    Lay the shortest of the plain wooden strips over the number 18 on the board.
    Sub Strip Board 4.JPG
  4. Take the 9 strip and cover up the numbers starting from the end. The last visible number is the answer.
    Sub Strip Board 5.JPG Sub Strip Board 6.JPG
  5. Then take the 8 strip and cover up the numbers starting from the end. The last visible number is the answer.
    Sub Strip Board 7.JPG
  6. next step
    Sub Strip Board 8.JPG
    record the equation and answer

Presentation Two

  1. step one
    Sub Strip Board 9.JPG
  2. next step
    Sub Strip Board 10.JPG
  3. next step
    Sub Strip Board 11.JPG
  4. next step
    Sub Strip Board 12.JPG
  5. next step
    Sub Strip Board 13.JPG

Points of Interest

Control of Error

Variations and Extensions

Material

This material is kind of a mess. Why can't the frame come right to the edges of the chart? Almost every kid who tries this the first time slides those strips of wood up against the frame and gets the answers all off by one.
And surely we can come up with a different system than using all those ridiculous wooden strips to cover up the numbers at the top. This is needlessly complicated.

Make Your Own

Strip Board pdf icon.jpg
Strip Board strip outlines pdf icon.jpg
Subtraction Fact Slips pdf icon.jpg
Printable Strip Board - in color Printable Number Strips - outlines Printable Subtraction Fact Slips

Where to Buy

Hello Wood $59.00 (vast improvement over the traditional material)
Thinkamajigs $28.95
Thinkamajigs $116.95 (AMI)

Further Reading