## Tuesday, October 18, 2011

### Math Monday: tally marks

I recently posted about how we’ve been studying skipcounting by 5’s.  Now that Aikman has mastered this, we are now discussing tally marks, using popsicle sticks.  (For those not familiar with Montessori, this is typically NOT taught in the primary (3-6) curriculum, but a part of the elementary (6-9) curriculum as a study on numeration.)

I first brought interest to this material by making the tally marks in front of him one afternoon.  With a hot glue gun, he and I made 20 sets of 5 tally marks.  During this time, I let him count the sticks in each bundle, letting him see that each group had 5 sticks in them.

The next day, I set them out on the shelves for him to discover..

In terms of presentations, my first presentation was simply, “This is a collection of 5 items. Let’s count them by 5’s.”

Subsequent presentations included:

a) drawing a number card (of the multiples of 5’s) and then counting them out.

b) picking up a group of 5-tallies from the box, counting them, and then finding the number card to match.

c) picking up a group of loose popsicle sticks, and then converting them to proper tally mark groupings.

d) rolling a dice to determine how many popsicle sticks to add, and then converting them to proper tally mark groupings.  (*** This is a personal favorite!)

e)  picking up a random number of 5-tallies and single sticks and counting them.

So far this is the last presentation that we’ve done for tallies.  I’ve discovered that he has a really hard time going from counting by 5’s to counting the single sticks (ie 5, 10, 15… 16, 17, 18), so I believe I’m going to have to do some type of practice with this… any suggestions out there?

For storage, the sets of tally marks, as well as 20 single popsicle sticks, are placed into a box together. I have also added a set of number cards to place in the box that count by 5’s to 100.

I’m linking up to Montessori Monday and Math Monday.