Cogito
Grade 2 Math · Chapter 8 · Lesson 6
Thirds
Three equal shares.
10 problems · about 12 minutes · 2.G.A.3
What this lesson teaches
The child partitions shapes into three equal shares and names them thirds.
- Three equal shares are called thirds.
- Three thirds make one whole.
- A third is smaller than a half and bigger than a fourth.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
3 problemsReview — Halves: How many halves make one whole?
Answer 2
Why Two halves make a whole.
Review — Cubes and Solid Shapes: How many faces does a cube have?
Answer 6
Why A cube has 6 square faces.
Review — Shapes by Their Sides: A shape has 6 straight sides. What is it?
Answer A hexagon.
Why 6 sides makes a hexagon.
Warm Up
Straightforward practice. Get the method working first.
3 problemsHow many thirds make one whole?
Answer 3
Why Three thirds make one whole.
Which is bigger, a half or a third?
Answer A half.
Why Fewer shares means each one is bigger.
How many thirds make one whole?
Answer 3
Why All three pieces.
Build It Up
The same ideas with more to keep track of.
1 problemHow many cuts make three equal pieces of a bar?
Answer 2
Why Fewer cuts than pieces.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
3 problemsWhich is smallest?
Answer A fourth.
Why More shares means smaller pieces.
Three Friends: A pizza is shared equally between 3 friends. What is each share called?
Answer A third.
Why One of three equal shares is a third.
Which Is Bigger: Which is bigger, a third or a fourth?
Answer A third.
Why Three shares are bigger than four shares of the same whole.