Natural Selection in a Concrete Way
your students outside on the lawn and scatter a box of colored
toothpicks (with even numbers of red, blue, green and yellow
toothpicks) across about a thirty-foot square patch of grass.
Ask the students to pick up as many toothpicks as they can find
in twenty seconds, then head back to the classroom. Ask the
students to count how many toothpicks they found of each color.
Keep a running tally of the counts. They will almost certainly
have found more red and yellow than green and blue. Explain
that this is a good, concrete way to introduce the idea of natural
selection to elementary-aged children.
What are the advantages to presenting concepts concretely before
you deal with the abstract ideas? How does this relate to the
"Zone of Proximal Development"? How does it relate
to Piaget's concepts of assimilation and accomodation?
Socio-Cultural Approach to Math
a double-digit addition or subtraction problem on the board
and cover it up. Tell the students that you are going to show
them a math problem and you would like them to solve it in their
heads in 20 seconds—absolutely no pencils or pens allowed.
After the 20 seconds has expired, invite the students to first,
share with the class how they felt about the exercise, then
to share the strategies they used to solve the problem. You
will find that the students used several different approaches,
such as adding tens and then ones, carrying as though they were
writing the problem on paper, adding ones to the first number,
then adding the tens, etc. Use this as a jumping off point for
discussing how people approach math problems in many different
ways. Explain that some mathmeticians actually solve multi-digit
addition or subtraction problems from left to right, rather
than the other way around. Discuss the implications for teaching
math to children.
What are the benefits of using a socio-cultural approach (letting
children discuss their various strategies) as we teach mathematics?
What are the drawbacks?