# A Balloon Weighs Less Than Nothing

## The Activities

1. Topic: Counting, Addition. Book: Math-terpieces by Tang.
2. Topic: Comparisons, Weights, Pan Balance. Given a Pan Balance, and 7 small toys.  Which toy weighs the most? The least?  If I tie a helium balloon to one of the buckets, what will happen?

The toys we tested.

The balloon weighs less than nothing!

3. Topic: Reflections. Fill in the reflection of a pattern on a pegboard. The dark blue pegs are the mirror.  We used a real mirror placed on the dark blue line to check our work.

A simple shape, reflected over the blue mirror line.

4. Topic: Puzzles, Logic. Book: Puzzles, by Wildsmith

## How did it go?

This week I led the younger circle.  We had only 3 kids this time, so I used all the materials that require taking turns.  The scale and pegboard are both quite fun, but it’s really hard for more than 3 kids to use them at once without extreme chaos.

#### Math-terpieces

This is a pretty book with a combination of famous artwork and counting problems. The kids all enjoyed taking turns finding groups of shoes that add up to 7, or stars that add up to 10.

#### Pan Balance

The kids noticed the pan balance, and wanted to use it right away.  I brought it, and the small toys over to the table.  I gave the kids a minute to play with the toys, and then asked them which toy was the heaviest.  They weighed two toys against each other and realized the side of the scale that goes down is heavier.  We kept the heavier toy in the balance, and then tried to find another, heavier toy.  Eventually we found that the heaviest toy was the set of keys.  I asked if we should check the keys against the bluebird.  One of the kids said we didn’t need to, because we knew the keys were heavier than the strawberry, and the strawberry was heavier than the bluebird.  I said that was a good point, but we tested it anyway, just to make sure.

Next we figured out which toy was the lightest.  All the kids enjoyed putting different toys in the buckets.  They all thought it was hilarious when the buckets slammed down hard enough to come off the scale.

I happened to have helium balloon from a birthday party the previous day.  I asked the kids to predict what would happen if I tied the balloon to one side of the empty scale.  They all agreed that the balloon would make the side of the scale go down.  I tied it on, and we all saw that the balloon side went up.  I said the balloon must weigh less than nothing, which was quite funny to the kids.

#### Pegboard Reflections

I had 6 simple shapes set up on the pegboard, and the kids took turns reflecting their shape across the blue mirror line. We use a real mirror to check our work, and learn what a reflection is.

This was pretty easy for all the kids, although my son wanted to check his work in the mirror to figure out which color to use.  Everyone loved the pegboard, but as predicted, it was hard to wait for their turn, even though there were only 3 kids.

#### Wildsmith’s Puzzles

This is  a really cute book that’s a mix of counting, pictures, and logic.  There were a few interesting pages.

One page shows 3 cracked eggs, with 2 chicks and one grown hen. How many chicks should there be? The two girls figured out there should be 3 chicks, because there are 3 eggs, but my son thought maybe the big chicken hatched out of one of the eggs.

Another page shows two kittens hiding under a mother goat, in a rain storm. Why are the kittens under the goat?  The two girls laughed because the picture shows the goat’s udder. One girl suggested maybe the kittens wanted to be peed on.  Eventually my son noticed that it was raining, and suggested the kittens wanted protection from the storm.