Parent guide · Grade 2 Math · Unit 3

Lesson 3.2 Regrouping Ones

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: Regroup 10 ones as 1 ten.
You need: Craft sticks and rubber bands
Dice
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: “69 + 10” Listen for: 79
- Ask: “26 + 70” Listen for: 96
- Ask: “29 + 20” Listen for: 49
- Ask: “18 + 70” Listen for: 88
- Ask: “27 + 20” Listen for: 47
Teach the new idea
Say this: “When the ones add to 10 or more, we regroup: 10 ones become 1 ten.”
Say this: “27 + 15: 7 + 5 = 12 ones = 1 ten and 2 ones.”
Say this: “Regroup: trade 10 of one place for 1 of the next place.”
Show how
Show: 28 + 65 = ___
Say this: “Ones: 8 + 5 = 13. Write 3 and regroup 1 to the tens.”
Say this: “Tens: 1 + 2 + 6 = 9. Write 9.”
Say this: “28 + 65 = 93”
Answer: 93
Show: Ruth gleaned 37 bundles of barley one day and 33 the next. How many bundles did she glean?
$bar model$
Say this: “Unknown: the total.”
Say this: “Bar model: two parts, 37 and 33; the whole is unknown.”
Say this: “Equation: 37 + 33 = ?”
Say this: “37 + 33 = 70”
Say this: “Answer: Ruth gleaned 70 bundles.”
Answer: 70 bundles. Ruth gleaned 70 bundles.
Practice together
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: 14 + 39 = ___
Listen for: 53
If stuck: Ones: 4 + 9 = 13. Write 3 and regroup 1 to the tens.
Ask: 29 + 17 = ___
Listen for: 46
If stuck: Ones: 9 + 7 = 16. Write 6 and regroup 1 to the tens.
Ask: 12 + 18 = ___
Listen for: 30
If stuck: Ones: 2 + 8 = 10. Write 0 and regroup 1 to the tens.
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
Watch for
- Writing 12 in the ones place.
Game: Race to 100
Roll two dice, make a two-digit number (like 3 and 5 make 35 or 53), and add it to your total. First to reach exactly 100 or more wins.
Narration
Say this: “Tell me what you learned today. Show me with your hands or the counters if you like.”
Listen for: Regroup 10 ones as 1 ten.
Daily habit
One-minute addition drill on Fridays. Mental math: add 10 or 20 to any two-digit number.

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.