**Equivalence Crisis Tray – Montessori Math Lesson**

**Equivalence Tray – Presentation I**

Invite the child to see some new work with the golden beads. Spread a mat: *“This is the equivalence tray. Some people call it the Crisis of Nine tray. Let'sd look at these beads and count them. We'll start with the units.”*

- Count the units from their tray into the mat below in a vertical line, touching each other.
*“Ten units is the same as a ten bar. When we have a ten bar we have to move to a new place. We can't stay in the unit's place anymore.”*- Use the same approach and language with tens/hundreds and hundreds/thousand: “
*Ten bars is the same as a hundred square. When we have a hundred square we have to move to a new place…”*

### Presentation II – Exchanging

- Return to the row of units: “Now,
*let’s count these again.”*Make a big deal of moving to the ten’s place and picking up a ten bar*“because ten units are the same as one ten.”*Continue on to the thousand cube by counting the hundred squares. - Summarize and quiz the child:
*“ten units make what? Ten bars make what?”*etc.

**Variations**

- Use separate mats for each quantity so the child must move his body considerably to count the beads
- Ask the child to give you or to bring to you various quantities. Occasionally ask for ten of something to check if the child understands the exchange.

**Extensions**

- Make a Take Home Booklet showing equivalence. So, ten units on one page and a ten bar on the opposite facing page. etc
- Draw or color the bead material

Have fun!

Marnie

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