# Subtraction With Strip Board

From Montessori Album

Subtraction With Strip Board | |
---|---|

Math - Memory Work | |

Level | Primary |

Age | 5+ |

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

## Contents

## Presentations

### Presentation One

- Take the material to a mat or table. Lay out as shown.
- The first page should have just one problem: 18-9=
- The next page should have two problems: 17-9= and 17-8=
- Take the 9 strip and cover up the numbers starting from the end. The last visible number is the answer.
- Then take the 8 strip and cover up the numbers starting from the end. The last visible number is the answer.
- next step

### Presentation Two

## 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

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

- Teaching Montessori in the Home: The School Years by Elizabeth G. Hainstock, pages 24, 66