Next week, cooks all over America will do one tricky calculation: if dinner is at 3:00, what time do I start? That’s elapsed time — and it’s math you’ll use forever.
A clock has two hands. The short hand tells the hour. The long hand tells the minutes. Let’s read some clocks together!
Red is the short hour hand. Blue is the long minute hand.
Let’s talk
What happens at our school at 8:00? What about at 12:00?
Count with me from 12 to 3 on the clock. How many hours is that?
What is your favorite time of the whole day? Why?
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From 12 to 3 is 3 hours — count them: 1, 2, 3! And 8:00 is when we have morning meeting, right now!
Try it
Be a clock! Use your arms as clock hands. Make 12:00 (both arms straight up). Now make 3:00 (one arm up, one arm out sideways). Now 6:00!
Cooking a Thanksgiving meal is really a backward-planning problem. You know when you want to eat. Everything else is subtraction.
Two unknowns to solve.
Let’s talk
The turkey takes 4 hours. What time does it need to go in the oven?
The rolls take 25 minutes. What time do they go in?
Now the tricky one: the turkey needs to rest 30 minutes after cooking, before you carve it. Does that change the start time? To what?
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Turkey: 3:00 − 4 hours = 11:00 a.m. Rolls: 3:00 − 25 minutes = 2:35 p.m. With the 30-minute rest, the turkey must come out at 2:30, so it goes in at 2:30 − 4 hours = 10:30 a.m. That half hour is exactly the kind of detail that makes dinner late!
Try it
Plan your own morning! You need to be at school by 7:45. Work backward: what time do you leave the house, eat breakfast, and wake up? Compare with a partner — who built in more cushion, and who is cutting it close?
Additional Notes/Activities
If additional activities are needed for the Morning Meeting, they will be added here.