Cogito
Kindergarten Math · Chapter 4 · Lesson 3
The Missing Part
You know the whole and one part. Find the other.
10 problems · about 9 minutes · K.OA.A.4
What this lesson teaches
The child finds a missing addend within 10.
- Sometimes you know the whole and one part.
- Count up from the part you know.
- Check by putting the parts back together.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
4 problemsReview — Breaking a Number Apart: 8 is 5 and how many?
Answer 3
Why Three.
Review — Taking Away: 8 − 3 = ?
Answer 5
Why Five.
Review — Adding in Any Order: 2 + 6 = ?
Answer 8
Why Eight.
Review — Counting On: 6 + 2 = ?
Answer 8
Why Eight.
Warm Up
Straightforward practice. Get the method working first.
3 problems6 + ? = 10
Answer 4
Why Four.
5 + ? = 8
Answer 3
Why Count up from five.
2 + ? = 6
Answer 4
Why Count up from two.
Build It Up
The same ideas with more to keep track of.
2 problems7 + ? = 7
Answer 0
Why Already there.
4 + ? = 9
Answer 5
Why Count up from four.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
1 problemThe Hidden Marbles: Nine marbles. Six on the table. How many in the bag?
Answer 3
Why Three.