Parent guide · Grade 2 Math · Unit 3

Lesson 3.4 Adding Several 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: Add three or four two-digit numbers.
You need: Dice
Pencil and crayons
Print: Worksheet A · Worksheet B · the lesson page (it also has a short video (3:15))

Steps

Warm-up
Do this: Ask these out loud. Your child answers out loud; no paper needed.
- Ask: “52 + 40” Listen for: 92
- Ask: “28 + 70” Listen for: 98
- Ask: “69 + 20” Listen for: 89
- Ask: “32 + 40” Listen for: 72
- Ask: “25 + 40” Listen for: 65
Teach the new idea
Say this: “Add a column of ones at a time; look for tens to make it quick.”
Say this: “With several numbers you may regroup 2 tens, not just 1.”
Say this: “Column: digits of the same place lined up.”
Show how
Show: 48 + 39 + 15 = ___
Say this: “Ones: 8 + 9 + 5 = 22. Write 2 and regroup 2 to the tens.”
Say this: “Tens: 2 + 4 + 3 + 1 = 10. Write 10.”
Say this: “48 + 39 + 15 = 102”
Answer: 102
Show: 21 + 11 + 33 + 22 = ___
Say this: “Ones: 1 + 1 + 3 + 2 = 7. Write 7.”
Say this: “Tens: 2 + 1 + 3 + 2 = 8. Write 8.”
Say this: “21 + 11 + 33 + 22 = 87”
Answer: 87
Practice together
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: 35 + 18 + 26 = ___
Listen for: 79
If stuck: Ones: 5 + 8 + 6 = 19. Write 9 and regroup 1 to the tens.
Ask: 30 + 22 + 16 = ___
Listen for: 68
If stuck: Ones: 0 + 2 + 6 = 8. Write 8.
Ask: 24 + 27 + 19 = ___
Listen for: 70
If stuck: Ones: 4 + 7 + 9 = 20. Write 0 and regroup 2 to the tens.
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
Watch for
- Regrouping only 1 when the ones add to 20 or more.
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: Add three or four two-digit numbers.
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.