# The Exchange Tray

From Montessori Album

The Exchange Tray | |
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Math - Introduction to the Decimal System | |

Level | Primary |

Age | 4 - 5 |

Prerequisites | Association of Beads and Cards |

Materials | Golden Beads: 10 unit beads 9 ten bars 9 hundred squares tray |

This activity teaches the child that 10 units are the same as 1 ten, that 10 tens are the same as 1 hundred, and that 10 hundreds are the same as 1 thousand.

## Contents

## Presentation[edit]

- Prepare a tray with 10 unit beads, 9 ten bars, and 9 hundred squares.
- Lay the beads out on a mat as shown.
- Count the unit beads, moving them down as you do (or moving them into a small bowl). "1 unit, 2 units, 3 units..."
- "10 units is the same as 1 ten." Have the child go to the bank and exchange the 10 unit beads for 1 ten.
- Bring the ten bar to the mat.
- Place it with the other ten bars.
- Count the ten bars: "1 ten, 2 tens, 3 tens..."
- "10 tens is the same as 1 hundred." Have the child go to the bank and exchange the 10 ten bars for 1 hundred square.
- Bring the hundred square to the mat. Place it with the other hundred squares.
- Count the hundred squares: "1 hundred, 2 hundreds, 3 hundreds..."
- "10 hundreds is the same as 1 thousand." Have the child go to the bank and exchange the 10 hundred squares for 1 thousand.
- Bring the thousand cube to the mat. "One thousand. Did you know that we had one thousand beads on the tray?"