Parent guide · Grade 2 Math · Unit 7
Lesson 7.2 Centimeters and Meters
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
- Measure in centimeters and meters.
- You need
- An inch ruler
- Pencil and crayons
- Worksheet A · Worksheet B · the lesson page
Steps
Do this: Ask these out loud. Your child answers out loud; no paper needed.
- Ask: “20 + 20” Listen for: 40
- Ask: “23 + 30” Listen for: 53
- Ask: “13 + 70” Listen for: 83
- Ask: “80 + 10” Listen for: 90
- Ask: “22 + 20” Listen for: 42
Say this: “Most of the world measures in metric units. 100 centimeters make 1 meter.”
Say this: “A centimeter is shorter than an inch: about 2½ cm make an inch.”
Say this: “Centimeter (cm): a small metric unit, about the width of a fingernail.”
Say this: “Meter (m): 100 centimeters.”
Show: 2 meters = ___ centimeters
Say this: “1 meter = 100 centimeters, so multiply by 100.”
Say this: “2 × 100 = 200”
Answer: 200
Show: The oak is 88 feet tall. The apple tree is 16 feet tall. How much taller is the oak?
Say this: “Unknown: the difference.”
Say this: “Bar model: a long bar of 88 and a short bar of 16; the difference is unknown.”
Say this: “Equation: 88 − 16 = ?”
Say this: “88 − 16 = 72”
Say this: “Answer: The oak is 72 feet taller.”
Answer: 72 feet. The oak is 72 feet taller.
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: How long is the bar, to the nearest centimeter?
Listen for: 10 cm
If stuck: The bar starts at 0.
Ask: How long is the bar, to the nearest centimeter?
Listen for: 4 cm
If stuck: The bar starts at 0.
Ask: How long is the bar, to the nearest centimeter?
Listen for: 13 cm
If stuck: The bar starts at 0.
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
- Reading the inch side of the ruler.
Each player guesses the length of a household object, then measures it. Closest guess earns a point. Use inches one day and centimeters the next.
Say this: “Tell me what you learned today. Show me with your hands or the counters if you like.”
Listen for: Measure in centimeters and meters.
Recite: 12 inches make a foot, 3 feet make a yard, 100 centimeters make a meter, 60 minutes make an hour.
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.