Doubling every day
Two plans run for 6 to 12 days. Plan A gives the same amount every day; Plan B gives 1 or 2 on day 1 and twice as much as the day before every day after. The student works out which plan has given more and by how much, how much Plan B gives altogether, or the first day Plan B is ahead.
Doubling starts slowly and then races ahead, so the answer depends on how many days there are: in about a third of the comparisons Plan A is still ahead. The working is a table with a column per day.
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What changes each time
- Plan A from 10 to 95 a day; Plan B starting at 1 or 2
- Cents for walking a dog, points in a reading challenge, coins in a game
- Which plan and by how much, Plan B's total, or the day Plan B takes the lead
More patterns, sequences and logic practice
- Skip counting (Grade 1)
- Repeating patterns (Grade 1)
- Hundred chart: 10 more and 10 less (Grade 1)
- Number sequences (Grade 2)
- Number machines (Grade 2)
- Multiples on a hundred chart (Grade 3)
- Ordering from clues (logic) (Grade 3)
- How many to be sure? (logic) (Grade 3)
- Truth-tellers and fibbers (logic) (Grade 3)
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- Take-away game (logic) (Grade 4)
- Cook it faster (Grade 5)
- Growing patterns (Grade 4)
- Bigger start or bigger raise? (Grade 4)