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Cogito

Grade 1 Math · Chapter 3 · Lesson 4

Practice Worksheet

The Hidden Part

You can see one part. Work out the other.

10 problems · about 11 minutes · 1.OA.B.4, 1.OA.A.1

NameDate

Figure — use these to answer the problems

Move the apples. Watch how one part tells you the other.
Red group
Tap one to move it across
Green group
Tap one to move it back
Apples in all9
Red group6
Figure 1

Warm-Up Review

From earlier lessons. Loosen up before the new work.

5 problems

  1. From “Taking Away”

    7 − 3 = ?

    Answer

  2. From “Counting Up To Subtract”

    9 − 7 = ?

    Answer

  3. From “How Many More To Make It?”

    3 + ? = 7

    Answer

  4. From “Facts to Ten”

    7 + 3 = ?

    Answer

  5. From “Doubles and One More”

    3 + 4 = ?

    Answer

Warm Up

Straightforward practice. Get the method working first.

3 problems

  1. Whole 9, one part 4. What is the other part?

    Answer

  2. Whole 6, one part 1. What is the other part?

    Answer

  3. Whole 7, one part 2. What is the other part?

    Answer

Build It Up

The same ideas with more to keep track of.

1 problem

  1. Whole 10, one part 6. What is the other part?

    Answer

Stretch Yourself

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

1 problem

  1. Sock Drawer

    Leo has 8 socks. 3 are stripy and the rest are plain. How many are plain?

    Answersocks