stock up on some energy with trail mix for this one, and bring water for the
Adult supervision | car odometer or
Watch with a second hand, or
Wire landscaping flag or other
marker for the halfway point
Here's a little real-world math
problem that also gains you some exercise! Here's the situation:
and Pierre are brother and sister. They are racing from their home to the
school. Sierra runs half the distance and walks half the distance. Pierre runs
half the time and walks half the time. They both run at the same speed and walk
at the same speed. Who arrives at school first?
Let's act this out to find the answer. You will need
at least two people. If you have a big group, have half of your group be
"Sierra" and the other half be "Pierre."
1. If you're in a group meeting at school or somewhere
else, use the school as your starting point, and decide on a neighborhood
landmark that's a reasonable distance away - maybe a half-mile, for example.
2. If you're at home, and school is not too far away,
make school the destination. (A "destination" - pronounced "dess tin A
shun") is a place you are going to.) If you're at school and there's a park a
few blocks away, that might make a good destination. Pick a specific ending
place, such as the slide in the park, or the front door of your school
3. First, let's figure out the distance. An adult
with a car can use its odometer, or an adult walking can use the pedometer, to help
you measure the distance between your starting point and the
destination. Don't forget to bring a wire landscaping flag or other marker so
that you can pinpoint the halfway mark when you get there.
4. After you've measured the distance, divide that
distance in half to find your halfway point. Let's say you measured the
distance as .6 of 1 mile - just over half a mile. Using your car odometer or
your walking pedometer, go again from your starting point toward the
destination, and stop at .3 of 1 mile - which is the halfway point.
5. Stick the landscaping flag in the ground,
temporarily. That's the point at which the student(s) playing "Sierra" should
stop walking and start running.
6. Now let's measure the time between the
starting point and the destination.
7. First, walk at an even pace from the starting point
to the halfway point. Record how long it takes you. Then, run back to your
starting point, again traveling at an even pace the whole time, and record THAT
amount of time.
8. Now add your walking time to your running time. Let's
say you come up with 15 minutes and 30 seconds. Divide that time by two. Your
answer would be 7 minutes and 45 seconds.
9. That's the amount of time it would take to run
halfway, and walk halfway, to your destination.
10. Now let's see
who gets there first!
should walk to the halfway point, and then run to the destination.
12. Carrying a
watch or stopwatch, "Pierre" should walk for half of the time, and then run
for the second half of the time.
Who will win?!?!
(Answer: Who gets there first? Pierre,
because he spends more time running than walking. The time spent going
faster is more valuable than the distance spent going faster, if you
divide them both in half)