Friday, February 19, 2010

Time continued...

We were working on applying time calculations today, so I posed a question:

"If [student A] was given detention for 1.4 hours and [student B] was given detention 1 hour 25 minutes detention, who would be in detention the longest?"

Students had a guess and then they reviewed the caterpillar for converting between time units.

We then did a number of calculations with some templates to show how a calculation could be constructed.
Eg
3.4 hours = _______ x ________ mins
= ______________ mins
2 122 131 sec = ________ ÷ _________ ÷ _______ ÷ _______ days
= ____ days
1 hour 20 mins = ________ x _________ + ________ mins
= ______________ mins
After we did that, students were just given a range of questions to solve without the templates.
Eg.
2.8 hours = ___________ minutes
12 hrs 12 minutes = ______ hours
12 hrs 12 minutes = ______ days
Then we revisited our original detention problem and a range of similar problems.
Students then practiced with math-joke type connect-the-answer-with-the-question exercise (the old worksheet with a bad, bad mathematics joke at the bottom to solve). Students were able to solve the majority of problems.
yay!
There's nothing to say that with a stronger group I couldn't have taught the same topic by teaching basic time facts (such as 60sec = 1 minute) and then relied on their application of multiplication and division, but in this case I'm glad I didn't do that, the look on the faces of my students when they realised time calculations made sense (that they had found difficult over a long period) was priceless.