A thousand seconds
Measurement, Level 2
Problem
What time is it now? What will the time be in a thousand seconds?
What is this problem about?
This problem develops the child's understanding of the size of a thousand while
practicing their use of seconds and minutes. The calculation in the problem can be
approached through either repeated addition or division. Using a calculator introduces
decimal numbers which will probably be unnecessarily confusing.
Achievement objectives
Measurement (level 2)
- read time and know units of time minute, hour, day, week, month and year
Mathematical processes
- devise and use problem solving strategies
Resources required
a clock
Blackline master of the problem (English)
Blackline master of the problem (Maaori)
Specific learning outcomes
The children will be able to:
- use seconds, minutes and hours
- discuss the size of a thousand
- read the time in digital or analogue form
Teaching sequence
- Introduce the problem by looking at the clock and posing the question:What time is it
right now?Write the time on the board using either digital or analogue form.
- Read the problem to the children.
What do you need to know to be able solve this problem? Make sure that the children
know that there are 60 seconds in a minute.
- Encourage the children to work in pairs to solve the problem. Ask that they record their
work, and write about the thinking that they used.
Share solutions
How did you and your partner find the answer?
Does anyone have a different answers?
Did anyone use a different strategy to come up with the same answer?
Extension problems
- What will the time be in a 1000 minutes?
- How many seconds are there until (give a time 3 hours 15 minutes later)?
Other contexts for the problem.
How high would a stack of a 1000 cubes be?
Solution
Now 1000 divided by 60 = 16 and 40 over. If the children use a calculator
of this problem they will have a decimal in the answer. They could use a calculator
to skip count in 60s up to 1000. Using this approach they would get to 960
after 16 minutes and have 40 seconds left. So 1000 seconds equals 16 minutes and 40
seconds.
Extension: 1000 minutes = 16 hours and 40 minutes
3 hours and 15 minutes = 3 x 60 x 60 + 15 x 60 = 11 700 seconds.