Winter definitely continues to grasp many areas of North America. And,
just like my family, I am certain that your family is eager for blustery spring
winds to blow away those pesky snow clouds.
Hopefully, it won’t be too long before the light and fluffy snowflakes
will be replaced by an ample supply of raindrops—the perfect way to wash away
the gray of winter.
This anticipation of spring is a great opportunity to provide not only
a science lesson but also a fun way to demonstrate the concept of ratios. By
using the relationship between snowflake density and raindrop density (i.e. the
Snow Water Equivalent), the kiddos can practice using ratios, skip counting,
and multiplication.
Why not go outside, scoop up a bucket of fresh fallen snow, and have
some winter-spring transition fun.
HOW CAN WE USE THE SNOW WATER EQUIVALENT
TO TEACH RATIOS?
“IT’S
A RATIO.”
“HORATIO
WHO?”
Every
time I hear the term ratio, I recall the scene where Opie
and Andy Taylor discuss ratios. Opie, most likely in the first grade, does not
understand the term. In fact, many children in K-2 have difficulty grasping the
concept. Add this confusion to the concept of comparing snowfall amounts with
rainfall amounts, and you have a recipe for a flood of misunderstanding.
This activity addresses both concepts in a fun yet scientific manner.
Finish it off with a snow cone treat and your children are bound to forever
remember that it takes a lot of snow to equal an inch of rainfall!
ACTIVITY DESCRIPTION: Children will observe changes in density by melting
snow. They will then use the melted snow to determine the ratio of rain to
snow. Children will use that information to predict how much rainfall there
would be if their area received rain instead of snow.
MATERIALS:
Fresh snow (or shaved ice if no
snow is available-results will vary)
Clear plastic cup
Clock and timer
Printouts of raindrops and
snowflakes
Camera (optional)
INSTRUCTIONS:
1. Prior to the activity, fill
the plastic cup with either snow or shaved ice. Show the cup to your children.
Explain that when snow melts
into water, the density (a measure of how compact an object is) will change.
Ask: When this snow melts, how much water will there be in the cup?
2. Place the cup on flat
surface and take a photo of it.
3. Record the time that the
observation begins and set the timer for 30 minutes.
4. When 30 minutes have passed,
look at the snow and record any changes. Take a photo. Set the timer for 30
minutes.
5. Repeat step 4 until the snow
has melted.
6. When the snow is melted
compare the children’s predictions with the actual amount of liquid in the cup.
Ask: How long did it take for the snow to melt? Why is there less
spaced filled in the cup? What could change the rate of melting? (Ex: placing
the cup in the sun, in front of a fan, etc.)
EXPLANATION:
When snowflakes combine with
other snowflakes, there is air between each one. When the snowflakes melt, air
is released, causing the water contained in the snowflakes to take up less
space. The snow and the liquid have the same mass (stuff), but have different
density.
7. Use the printouts of the snowflakes
and raindrops to represent the ratio of inches of snow to the corresponding
inches of rain, as shown.
8. Discuss the differences that
could happen if the snowfall fell on a different day. For example, when
temperatures rise, snowflakes have a greater density. Therefore, the ratio of
snowfall to rainfall would change.
9. Complete the lesson by making snow cones. Remind the children that
while their snow cone cups may appear full, there is very little water inside.
EXTENSION ACTIVITIES:
1. Completion of the snow melting portion of this activity provides an
opportunity to reinforce telling time to the hour and half hour. Children in
K-1 can use the photographs created by the experiment to sequence the melting
process and matching the corresponding time to the correct image.
2. This lesson also provides and excellent opportunity to practice skip
counting and multiplication. Print multiple copies of the raindrop and
snowflake printables to use with both concepts. It is also possible to begin
basic algebra concepts by replacing the snowflake with S and the raindrop with
R.
