TEACHER EDITION
Place Value — Part 2
Math Book 3 · sheet 3
Warm-up — yesterday: Place Value — Part 1
What is the value of the 7 in 1,742?700
What we are learning
A number can be taken apart into its places and put back together, and it is the same number either way.
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
2,406 written out.
2,406
2
Thousands.
2,406
2,000
3
Hundreds.
2,406
2,000
2,000 + 400
4
Tens — there are none, so nothing is added.
2,406
2,000
2,000 + 400
2,000 + 400 + 0
5
Ones. Put it back together and it is the same number.
2,406
2,000
2,000 + 400
2,000 + 400 + 0
2,000 + 400 + 0 + 6 = 2,406
Practice
I DOteacher builds it, nothing erased
Write 3,185 in expanded form.
- 3,000 + 100 + 80 + 5
WE DO 1together, on whiteboards
Write 7,264 in expanded form.
One term for each place, largest first. Boards up.
- 7,000 + 200 + 60 + 4
WE DO 2together, on whiteboards
Write 4,908 in expanded form.
One place here is empty. Decide what to do about it.
- 4,000 + 900 + 8
YOU DOindependent, from the book
Book 3A p.14 — the Do section, clipped onto the slide
Ask yourself: “Have I accounted for every place?”
Watch for
4,908 forces the judgement about the empty tens: writing + 0 is not wrong and leaving it out is conventional. Accept either, but make the child SAY the tens place is empty — silence there is what causes 4,908 to be read as 498.
4,908 forces the judgement about the empty tens: writing + 0 is not wrong and leaving it out is conventional. Accept either, but make the child SAY the tens place is empty — silence there is what causes 4,908 to be read as 498.