Students will learn to reframe a subtraction problem as a missing addend addition problem. For example, to solve 13 - 5, students think 'What number do I add to 5 to get 13?' This builds the connection between addition and subtraction as inverse operations.
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Understand Subtraction as an Unknown-Addend Problem
Grade 1 · Properties and Strategies for Addition and Subtraction · question 1 of 3
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12 rungs. A star at the top.
11 = + 3
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Subtraction can be a missing addend.
You ask, plus what makes the whole?
8 + ? = 13. Start at 8 and count on to 13: 9, 10, 11, 12, 13. That is 5, so 8 + 5 = 13.
The whole is the 2 parts together, so one part and the missing part make 13.
Counting on from 8 counts only the missing part.
A take-away hides the same thing: 13 − 8 is the 5 that makes 8 into 13.
Start at the part you know. Count on to the whole. The count on is the missing part.
Adding the 2 numbers you see: 8 + 13 = 21.
13 is the whole already. Count on from 8 to 13: 5.
12 − 9 = ___ — 3. Think 9 + ? = 12: count on from 9: 10, 11, 12. That is 3.
Let's figure out thirteen minus five.
Here's a clever trick! Instead of taking away, we can think about adding.
We ask ourselves: five plus what number equals thirteen?
Let's use a number line to find the missing number.
We start at five.
And we want to reach thirteen.
Now let's count the jumps from five to thirteen.
One, two, three, four, five, six, seven, eight. That's eight jumps!
So five plus eight equals thirteen.
That means thirteen minus five is eight. Nice work!
While they climb, your page writes one true line to ask about tonight, and a short note each Sunday.
A chessboard has 64 squares — share them out between the 8 rows and each row holds exactly 8.
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Maya earned 2 stars this week — Interpret multiplication as equal groups, which took 6 answers over 3 days before its star landed 3 days ago and Multiply by 6, 7, 8 and 9. Next up: Divide within 100.
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14 days of every skill, practice packets, Fluency sheets and up to four students. No card.