Eli has a box of baseball cards and a lot of friends, and he wants to know which piles will come out even before he starts dealing.
Not started yet.
By the end of this lesson your student should be able to use the divisibility rules for 2, 3, 4, 5, 6, 9 and 10 on any whole number, and explain why each rule works as a test.
🚨 Using the digit sum for the wrong rule, such as checking 4 or 5 by adding the digits. The sum is only for 3 and 9.
Checking 4 by the ones digit alone, so every even number looks like it passes. Only the last two digits matter.
Forgetting that 6 needs both 2 and 3, and calling a number divisible by 6 because it passed just one of them.
Have the student pick a number and predict which rules it passes, then check each prediction with a calculator. The rules feel like magic until he sees them hold ten times in a row.
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Before You Start
The words this lesson uses. Tap a card to see what it means, then come back to them whenever a question uses one.
Part One
Questions about the story you just read. Pick your answer straight off, or press Find it in the story if you would rather hunt for the sentence first.
Part Two
The word cards are at the top of this page. Look back at them as often as you need, then answer.