In Variables and Expressions you had the rule and the number, and you found the answer. This time you have the answer, and the number is missing.
Not started yet.
By the end of this lesson your student should be able to look at an equation like 2n = 14, find the number that makes it true, and check it by putting that number back in.
It is the reverse of U1-L8. There the student had 2n and a value for n and worked out the answer. Here the answer is known and n is the missing piece.
Before any letters, write 2 x 5 = 14 and ask whether it's true. Then 2 x 7 = 14. The student should hear an equation as a claim that can be right or wrong.
Then write 2n = 14 and ask the same question. The honest answer is that you can't tell yet, and that answer is the doorway into the lesson.
🚨 Students often guess once, see it's wrong, and guess again at random. Push them to read the wrong guess: was the result too big or too small? That tells them which way to move.
Some students stop at the number and never check it. The check is the step that makes it an answer rather than a guess, so make it a habit: put the number back in and see if the sentence is true.
Keep a small table as you guess: the guess, what it gives, and whether it's too big, too small or right. Writing the verdict down is what turns guessing into a method.
When a fact solves it outright, like 12r = 120, ask the student what times table fact they used. Naming the fact is the mental math.
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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.