TEACHER EDITION

The Number 0

Grade 1 · Lesson 2 · Dimensions 1A p.7
Math Book 1 · sheet 2
Warm-up — yesterday: Numbers to 10
How many? ● ● ● ● ● ●
6

What we are learning

Zero is a number too. It is how many are there when there are none.

How it is done — keep this beside you

These steps stay on your page while you work. If you get stuck, find the step you are on and read it again before you put your hand up.

1
Three counters in the box.
[ ● ● ● ] = 3
2
I take one away. Now two.
[ ● ● ● ] = 3 [ ● ● ] = 2
3
I take another. Now one.
[ ● ● ● ] = 3 [ ● ● ] = 2 [ ● ] = 1
4
I take the last one. The box is empty — but I still need a number.
[ ● ● ● ] = 3 [ ● ● ] = 2 [ ● ] = 1 [ ] = ?
5
Empty is zero. We write it 0.
[ ● ● ● ] = 3 [ ● ● ] = 2 [ ● ] = 1 [ ] = ? [ ] = 0

Practice

I DOteacher builds it, nothing erased
How many birds are on the branch? (an empty branch)
  1. There are none.
  2. None has a number, and the number is 0.
  3. 0
WE DO 1together, on whiteboards
How many apples in the empty basket?
Boards up. Write the numeral, not the word.
  1. 0
WE DO 2together, on whiteboards
Count down with me: 3, 2, 1, ___
What comes after 1 when we are counting down?
  1. 0
YOU DOindependent, from the book
Book 1A p.7 — the Do section, clipped onto the slide
the book page
Ask yourself: “Is there none, or is it just hard to see?”
Watch for
Children write nothing at all instead of 0 — a blank board is not an answer of zero and must not be accepted as one. That distinction is the lesson.