Friday, 11 July 2014

Brain games, rain data and the metric system

Truthfully, don't waste your money!
I bought this for when I'm sitting
with a hospice client who sleeps.

You can buy books, or dear computer applications, which give you brain gym-type exercises, or you can create your own fun and games!

I love recording the rain data, but then I loved teaching math, too. Data is fun to collect, and keeps me amused.

I've got 3 gauges, now. Small, medium, and an electronic one. The medium-sized one begins at 0.5 cm (even though we measure rainfall in mm = 5mm), the smaller one begins at 10mm. Someone missed the math lesson! We converted to metric measurement from Imperial when I was at the Faculty of Education (1981). That was fun to master!

This ladder is for area, but it works for all metric metric conversions.

Metric measurement
I made my students memorize this chart, and it was a great little quiz for them. When you move each step on the ladder, you simply move a decimal place. Therefore, 10.0 mm = 1.0 cm. We don't use dm (decimetres or decametres), and we use hm for large farms, etc., but they need their place on the ladder. So to change millimetres to metres: 100.0 mm =  0.100 m, you climb three decimal places up the ladder, with the decimal going three places over.  This requires you to know that there are invisible decimal places for a whole number. As well, you cannot write a naked decimal; we require a 0 in front of the decimal place in our final answer! Nor do we begin a sentence with a number, either. But many journalists failed this lesson, too.

The new gauge is quirky!
Back to my gauges, which are just plain wrong. Blame a designer who missed the math lesson, or a US-based manufacturer.
Thing is, the first two usually agree, but the electronic one is very different. It only registers in inches, and I have to convert it to metric. Even so, it reported 0.45" = 11.43mm. The other two agreed and reported 18mm = 0.7" or rain.

Not only this, but the battery-powered gauge was a twitch to set up. You have to put the batteries in the measurement part, which has a little cup which fills, tips, and registers on the main gauge. Then you put the batteries in the monitor, set it 3 -  5' away, and wait 15 minutes for them to become friends. It took me 4 tries to remember all this and do it all correctly, then it took another 3 days for enough rain to fall for it to think it had a job to do.

The other two gauges managed to collect 1mm of water in the days between, after a quick, but insignificant dump of rain. I think I wasted my money!
Unfortunately, we don't measure rain in cm, as on the gauge.
1.8cm = 18mm = 0.7"

2cm = 0.8"

This collects the water, then flip and dumps it out.
Communicating with the metre on the wall.

It seemed simple enough!
It only reports inches!


William Kendall said...

I was educated in the metric system, which fits so nicely- everything divides by tens. That said, I still think in Imperial for my height, six feet.

Red said...

I wish I'd seen the ladder for area. We went off the rails for metric when many teachers insisted on teaching conversion to the English system. we'd have been much better off to only teach the metric system.

Olga Hebert said...

I remember that chart! My grand son is all about math and math games. He doesn't get it from my side of the family, though.