### The Mathematics of a Hail Storm

Kansas had an absolutely terrible storm Sunday night.  The sky was a murky green (this is never a good sign), and the hail was the size of golf balls.  It broke three of our four basement windows; so, we had glass everywhere plus hail stones were coming into our family room like crazy.  We just stuffed the windows with pillows and tried to clean up.  Our neighbors have siding damage that looks like someone went through our neighborhood with a machine gun when instead it was the force of the hail.  When the storm let up, everyone was outside and most were thanking God for sparing our homes.  Hail was laying everywhere in piles; so, my husband, being the scientist he is, was examining some of the big pieces.  He showed me how the hail was formed.

He explained that hail is created when raindrops are lifted up into the atmosphere during a thunderstorm and then super cooled by temperatures below freezing, turning them into balls of ice. The faster the updraft on these balls of ice, the bigger they can grow. On the hailstones found in our yard, we could actually see several rings inside of them which indicated they were cycled through the thunderstorm more than once. What started out as a minute raindrop became a golf ball sized chunk of ice. According to Dr. Dick Orville of Texas A & M University, large hailstones have been clocked traveling more than 90 miles per hour. I don’t know how fast these golf ball sized ones were traveling, but fast enough to make huge holes in aluminum siding.

Let’s look at the math of concentric circles.  Concentric means two or more circles of different sizes that all have the same center -- like a bulls eye target.
On the right is a picture of one of “OUR” hail stones. If you look closely, you can see four different circles, (a pattern) one inside the other.  That means it was recycled through the thunderstorm at least four times.
AND it was not only hard, but heavy.  According to the Internet, the largest hailstone ever recorded in the United States occurred in 1970 in Coffeyville, Kansas which is about two hours southeast of Wichita.  It was a stone that weighed 1.6 pounds and measured 5.5 inches when it fell. YIKES!!  I am glad I missed that one.

﻿
 Ice Investigation

Since ice seems to be the theme of this post, I want to mention my newest Teacher Pay Teachers resource entitled Ice InvestigationThis 20 page resource is a six lesson science investigation for grades 3-4 which uses ice cubes.  The inquiry guides the student through the six steps of the scientific method.  The unit consists of a three page student investigation organizer, a property word list, an optional student checklist, and a four point grading rubric for the teacher.  If you are interested, just click under the cover on your right.

### Divide to Conquer?

As presented in the posting of April 10th, there is another way to approach long division.  However, since many of you are required to present it the long way, here are a couple of ideas to make it easier for your students.

First of all, have the students use graph paper.  The squares help to keep the numbers aligned which seems to be a problem for many students.  If you don't have graph paper, you can download free templates at Donna Young's Free Graph Paper and make your own.  I like the idea of separating the problems with lines to ensure there is no cross over from one problem to another.

Secondly, try using the mnemonic of Does McDonald's Sell Cheese Burgers.  I've  see this acronym many times on Pinterest, but usually the C is omitted.

Check means that after the student has subtracted, they should check to see if the remainder is smaller than the divisor.  If it is equal to or larger, then they enough was not taken out of the dividend.  This is a step often skipped when long division is taught; yet, if the student doesn't check and make the needed correction, the answer (quotient) will be wrong.

In order to learn division, the student must first have a good understanding of multiplication. Students don’t need to perfectly know all of the times tables, but a majority of the facts or having a reasonably quick strategy to figure out the answer is necessary.

Start by practicing division using the number series the students can easily skip count such as 2 and 5. Then gradually move up to nine.  After that, move to division by double digit numbers using 10 since most students know how to skip count by 10.  Once the concept is understood, teaching division will become more about guided practice to help your child to become comfortable with the division operation which, in reality, is a different kind of multiplication practice.