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Cogito

Grade 1 Math · Chapter 2 · Lesson 6

Practice Worksheet

Finding the Missing Part

Work out the number that is hiding.

10 problems · about 12 minutes · 1.OA.D.8, 1.OA.C.6

NameDate

Figure — use these to answer the problems

Change the known part or the whole. The box works itself out.
Known part4
Whole9
Figure 1

Warm-Up Review

From earlier lessons. Loosen up before the new work.

4 problems

  1. From “What Does Equals Mean?”

    What does the equals sign mean?

    • Both sides are the same amount.
    • The answer comes next.

  2. From “Adding in Any Order”

    3 + 5 = 8. So what is 5 + 3?

    Answer

  3. From “Counting On With Pictures”

    Start at 9. Count on 1. Where do you land?

    Answer

  4. From “Counting On”

    8 + 2 = ?

    Answer

Warm Up

Straightforward practice. Get the method working first.

3 problems

  1. 5 + ? = 9

    Answer

  2. 3 + ? = 10

    Answer

  3. 4 + ? = 7

    Answer

Build It Up

The same ideas with more to keep track of.

1 problem

  1. 6 + ? = 10

    Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

2 problems

  1. 2 + ? = 9

    Answer

  2. The Bookshelf

    Leo needs 8 books. He has 5 already. How many more does he need?

    Answerbooks