Parent guide · Grade 2 Math · Unit 2

Lesson 2.3 Comparing Three-Digit Numbers

Written for the parent. Read the Say this lines aloud as they are, or in your own words. Answers for you are marked Listen for.

At a glance

Time: 5 sessions of 20–25 minutes
Goal: Compare and order three-digit numbers.
You need: Pencil and crayons
Print: Worksheet A · Worksheet B · the lesson page

Steps

Warm-up
Do this: Ask these out loud. Your child answers out loud; no paper needed.
- Ask: “What number is one hundred more than 308?” Listen for: 408
- Ask: “What number is one hundred more than 775?” Listen for: 875
- Ask: “What number is one hundred less than 522?” Listen for: 422
- Ask: “What number is one hundred less than 714?” Listen for: 614
- Ask: “What number is one hundred more than 531?” Listen for: 631
Teach the new idea
Say this: “Compare the hundreds first. If they match, compare the tens, then the ones.”
Say this: “482 > 479 because 8 tens is more than 7 tens.”
Say this: “Compare: decide which is greater, less or equal.”
Show how
Show: Write <, > or = : 349 ___ 373
Say this: “Compare from the left. The first place that differs is the tens: 4 and 7.”
Say this: “349 < 373”
Answer: 349 < 373
Show: Write in order from least to greatest: 703, 606, 103, 772
Say this: “Compare the biggest place first, then the next place.”
Say this: “103 < 606 < 703 < 772”
Answer: 103, 606, 703, 772
Practice together
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: Write <, > or = : 433 ___ 504
Listen for: 433 < 504
If stuck: Compare from the left. The first place that differs is the hundreds: 4 and 5.
Ask: Write <, > or = : 148 ___ 206
Listen for: 148 < 206
If stuck: Compare from the left. The first place that differs is the hundreds: 1 and 2.
Ask: Write <, > or = : 530 ___ 169
Listen for: 530 > 169
If stuck: Compare from the left. The first place that differs is the hundreds: 5 and 1.
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
Watch for
- Comparing only the ones digits.
Game: Biggest Number
Each player draws three digit cards and arranges them to make the biggest number possible. Read it aloud. Biggest number wins.
Narration
Say this: “Tell me what you learned today. Show me with your hands or the counters if you like.”
Listen for: Compare and order three-digit numbers.
Daily habit
Count by hundreds to 1,000, by tens from any number, and by fives to 100.

Spread over the week

5 sessions of 20–25 minutes. Stop while it is still going well.

Session 1. Warm-up, then teach the new idea (steps 1 and 2).
Session 2. Warm-up again, then show how with the examples.
Session 3. Practice together, then play the game.
Session 4. More practice on the worksheet, and the daily habit.
Session 5. Quick check: narration and a few practice items. Move on when it is mostly right.