TEACHER EDITION

Comparing and Ordering Numbers

Grade 4 · Lesson 5 · Dimensions 4A p.20
Math Book 4 · sheet 5
Warm-up — yesterday: Number Patterns
What comes next? 5,000 4,750 4,500 ___
4,250

What we are learning

Compare from the left, and when the numbers have different lengths the longer one is greater — but line them up before you trust that.

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
Compare 48,215 and 9,806.
48,215 9,806
2
Count the digits: five against four.
48,215 9,806 5 digits vs 4 digits
3
More digits means greater, so 48,215 wins.
48,215 9,806 5 digits vs 4 digits 48,215 > 9,806
4
Now 48,215 and 48,251. Same length — compare from the left.
48,215 9,806 5 digits vs 4 digits 48,215 > 9,806 4=4 8=8 2=2
5
First difference is the tens: 5 against 1.
48,215 9,806 5 digits vs 4 digits 48,215 > 9,806 4=4 8=8 2=2 48,251 > 48,215

Practice

I DOteacher builds it, nothing erased
Order least to greatest: 32,105 3,215 32,150
  1. 3,215 has four digits — it is least.
  2. 32,105 and 32,150 differ at the tens: 0 against 5.
  3. 3,215 32,105 32,150
WE DO 1together, on whiteboards
Order least to greatest: 71,400 7,140 71,040
Count digits first, then compare from the left. Boards up.
  1. 7,140 71,040 71,400
WE DO 2together, on whiteboards
Order least to greatest: 60,009 60,090 6,900
The zeros matter here. Line the numbers up before deciding.
  1. 6,900 60,009 60,090
YOU DOindependent, from the book
Book 4A p.20 — the Do section, clipped onto the slide
the book page
Ask yourself: “Same number of digits? Then compare from the left.”
Watch for
60,009 and 60,090 differ only in places most children skim. Have them write the two numbers one above the other, aligned right — the comparison becomes visible and the method transfers to decimals in Grade 5.