## Tuesday, December 11, 2018

### Finishing Up Measurement

Our older homeschool group has now flowed into play writing and a study of improv, but we still used some of our classroom time last week to work on Measurement. It's such a fun topic... the kids weren't quite ready to let go.

Estimation Wall

We used last week to complete our Measurement main lesson books with numbered pages, tables of contents, and front and back covers.

We also continued with the Estimation Wall. On Monday we did a small bottle of bubble stuff (121 grams). That was very interesting because the front of the bottle had a metric measurement on it (milliliters) but of course we needed to know mass, not capacity. On Tuesday we did two items with similar volumes, a cotton ball (1 gram) and a large marshmallow (6 grams). On Thursday we did a stapler (438 grams).

Here is the Final List of Estimation Wall Items in order of mass (which is why sticky notes on the chalkboard are helpful... you can move them around):

stapler - 438 grams

red onion - 346 grams

bubble stuff - 121 grams

lemon - 75 grams

chalkboard eraser - 45 grams

large marshmallow - 6 grams

poker chip - 3 grams

cotton ball - 1 gram

Again, we left all of the sticky notes up throughout, to help them have more information and fine-tune their estimates.

On Friday we flipped the estimation activity around a bit. Instead of me producing an item and asking them to estimate the mass, I gave them an amount in grams and they had to try to measure that amount and then check their guess for accuracy. It was 60 grams of sugar. I went first, so that we could have a number to get us going. I fell far short, with an amount of 25 grams. We measured the sugar into a clear plastic cup (13 grams) with a spoon and we were able to add more sugar or take some out, before being happy with the quantity and pouring it onto the kitchen scale. We sat in a circle and went all around the circle, watching each quantity measured. The last two people, of course, had the most experience with watching incorrect guesses and they were both able to estimate fairly precisely, coming up with 61 grams of sugar! This activity went with the Rainbow Density Experiment.

Science Experiments

If you're interested in a few fun at-home science experiments to follow up on this, here are two I recommend:

Rainbow Density Experiment
The Rainbow Density Experiment (PDF, print pages 6-7) uses four different solutions of sugar and water, plus food coloring. It is very easy to do at home. The measurements are given in both metric and imperial. I tried this one and it worked beautifully! The most dense sugar-water solution (60 grams of sugar in 3 tablespoons of water) layered on the bottom, with each successively less dense solution layering nicely on top. Since the children know that density is the relationship of mass to volume, and they can see that they are changing the mass of the sugar each time while keeping the same volume of water, they can easily understand this experiment. Revisiting the Galileo thermometer discusssion is helpful here too.

Snowball Launcher: Testing Newton's Second Law of Motion
The experiment which goes with Tuesday's items (the cotton ball and the large marshmallow) also has to do with the relationship of mass to volume. These two items are about the same size but they have very different masses. Snowball Launcher: Testing Newton's Second Law of Motion is a fun activity to explore how far they would go with the same force applied to them. The worksheet (this item is FREE on TpT) is meant to follow up on a Physics lesson, so it talks about formulas a bit (Newton's second law is F=ma) but you could skip that part and just do the activity and observe the results and leave them for your child to think about. You need tape, an old file folder, and a meter stick, plus the cotton ball and large marshmallow. Also easy to do at home!

Structured Word Inquiry

We also talked about measurement in SWI on Friday, looking at the prefixes on the metric stair. This was a very interesting discussion. It turns out that the steps up from the base unit (x10 deka, x100 hecto, x1000 kilo) all come from Greek and the steps down from the base unit (1/10 deci, 1/100 centi, 1/1000 milli) all come from Latin. We also discovered that the base units (liter, meter, gram) are very old words which come to us from both Greek and Latin! We had a great conversation about other words where we see those same prefixes, and what they mean. Words written in the lower left hand corner of the board are ones we were not sure about. I welcome your thoughts about other words to add to these lists!