MILLION SECONDS,
BILLION SECONDS
Another idea that I often used to show the stunning power of mathematics was fairly simple. How long does it take a person to become one million seconds old? The answers I usually got from students were way off (that's what makes it interesting). We fairly soon could work out together that a person reaches one million seconds in a little over 11.5 days. So then I asked them to figure out how long it would take for a person to reach one billion seconds old. I might ask them if they thought they had already reached a billion seconds. Most thought they had since they had reached one million seconds in less that two weeks of life. Of course I wouldn't be using this problem if it came out the way most kids thought it would. Either later in that period or the next day, the students were stunned to find out that they would not become one billion seconds old until they were approximately 31.7 years old. Again most adults are amazed by that answer also.
This problem can be used in a variety of ways. One extension I had them do was to figure out on which day they would reach one billion seconds. That is not easy because of leap days and so forth, but also not that interesting to most of my students because it was so far away. For my 7th and 8th graders it was more interesting to figure out when they would be 5 000 days old. I had them assume that they had been born on noon of their birthday.
5 000 days is about 13.7 years so it was between their 13th and 14th birthday. I told them that if they came to me on their 5 000 day old birthday (and could prove to me that it was the right day) I would give them a little present. If they had already passed that day, they had to tell me what day it was and if they were correct then they got the present. The present was something small and inexpensive and the same for everyone that year. If the 5 000 day old birthday happened in the summer they could see me just before school got out or the first day of school the next year.
The creative teacher can find other uses for this situation, depending on the age and ability of their students.
Adults can figure out when they will reach or did reach one billion seconds. Those of us who are a little older can figure out when we will be two billion seconds old. Maybe you don't want to do that! Some of the students liked to use this information with their parents birthdays. Don't forget that problems like this can show the power and fun of doing math. Things like this help kids to think in a more mature and logical way.
60x60x24 =86 400 seconds in one day
1 000 000 / 86 400 = about 11.57 days
1 000 000 000 / 86400 = about 11 574 days
11 574 / 365.25 = about 31.7 years
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