Drop the whole cycles, jump the whole units, and only count what is left over. When several things share the time, draw each as a bar, then see how the bars meet.
- 1Repeating Patterns5:59
- 2Totals over Cycles5:12
- 3Calendars6:30
- 4Elapsed Time5:41
- Now playing: 5Overlapping Time Periods3:55
- 6Time Spans4:11
Cycles and Time: Overlapping Time Periods
Methods in this video
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- 1
Same time? Count down the column
When to use it: Several things each take up a stretch of time (lights, machines, rosters, planting months) and are laid out in a time chart or table. The question asks how many happen at the same time, the longest continuous stretch, or which months suit both.
- When the question says 'at the same time', stop reading along a row and count down the column.
- Write how many are on in each cell, then join up the cells that count and measure them.
- The stretch does not have to be the same pair all the way; check the whole chart before choosing the longest.
- 'Both' means ticks in the same column, not adding the two lengths together.
Practise exam-style questions with these methods
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