showing and we had to make
the number 12, then we would
flip over 16, 2, and 1 so that only
numbers that are showing are 8
and 4 because if you add them
together, you get 12. So in binary,
it would be 01100. You have to
attend to precision when doing
binary numbers.
For more ideas on teaching about
computer science “unplugged,” I have
found csunplugged.org and learn.
code.org to be outstanding resources.
Robotics Teach Problem Solving
NXT Mindstorms, Lego’s programmable robot kits, is another powerful
tool that fosters critical thinking,
problem solving, and collaboration. I began by setting up a series of
Here’s how one of the third graders
responded:
In binary numbers, I use math
practice number 6 (attend to pre-
cision) when doing code. Binary
numbers are the digits 0 and 1.
Code for binary numbers is doubling one number starting with
one and writing them in 0 or 1.
You see, trying binary numbers
with cards makes it easier. We did
it in class once. First, our teacher
made us cards that say 1, 2, 4, 8,
and 16. Cards that are showing
are 1. Cards that are not are 0.
Then our teacher, Mrs. Mak, said
a number and we had to put the
cards face-down if they did not
equal the number Mrs. Mak said.
For example, if all the cards were
A student created this animation in Scratch to illustrate the idiom “Hold your horses!”
challenges for my students, such as
having the robot travel accurately in
a straight line from a starting point
to the finish line. We then moved
on to more complex robot obstacle
courses involving mazes and figure
eights.
It was amazing to see my students
ask one another questions, engage in
mathematical reasoning, and even
argue over the best way to complete
the challenge. They pulled out rulers, measuring tapes, and calculators.
Then they debated the merits of programming the robot using number of
rotations, time in number of seconds,
or number of degrees.
The most valuable discussions occurred when students did not experience immediate success. Rather than
step in with the answer, I asked more
questions to ignite their thinking. For
example, when they saw that the robot traveled only about half the length
of the course, they began to investigate by tracing back through their
steps to see where their programming
had gone awry.
They discovered the importance of
being consistent with the systems of
measurement. Instead of measuring
the circumference of the robot’s tires
in inches, as they had done with the
length of the course, they measured
it in centimeters. These learning experiences make indelible impressions
on my students as they persevered in
solving problems collaboratively.
