## Monday, July 2, 2012

### DOG DAYS MATH

Boy, is it HOT out there!!!  If the temperature outside is 100 but air conditioning keeps the atmosphere inside at 85 degrees, what is the percent change when you come in from the heat?     (100-85)/100........(the original amount minus the new amount) divided by the original amount).......the amount of change divided by the original amount.....The air inside is 15% cooler than the air outside.

In times of extremes, like in the weather, even the kids are aware of numbers.  What a great opportunity to demonstrate a few math concepts like percent change.

Here's another one.  The days are getting shorter.  Yesterday the sun rose at 5:14 and set at 8:24.....that's 15 hours and 10 minutes......910 minutes (multiplication).......tomorrow the sun will rise at 5:16 and set at 8:21.....that's 15 hours and 5 minutes.  [These are simple arithmetic problems and the times are only samples and not accurate.]  Students can look up sunrise and sunset on the computer and do the math on the calculator.  Now, calculate the percent change.  For what portion of the day is the sun up?  (tomorrow: 905/1440)  Can you use ratios to predict the number of minutes of sunshine the day after tomorrow?  next week?

You may feel more comfortable sitting in front of a fan, but is there a difference in your body temperature just because of the moving air?  Take your temperature with and without the fan.

Is there a candy thermometer in the kitchen?  How hot will a bowl of water get if you set it in the sun?  Will a smaller container get hotter?  more quickly?  glass versus metal?

Will warm water heat up faster than ice water if identical containers are set out in the sun?  Will boiling water cool off at the same rate that warm water heats up if both are put in the sun?

These are teachable moments because even the youngest students are aware of the extreme heat.  Whatever the student's age, there are math and science questions that can be related to today's extraordinary weather.  What questions can your kids come up with?  And how can an answer be found?.....The Teachable Moment for The Normal Genius in each of our kids!!