Parent guide · Grade 2 Math · Unit 8

Lesson 8.3 Arrays and Repeated Addition

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: Write repeated addition for an array.
You need: A few cups
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: “6 + 8” Listen for: 14
- Ask: “7 + 5” Listen for: 12
- Ask: “6 + 3” Listen for: 9
- Ask: “7 + 4” Listen for: 11
- Ask: “5 + 9” Listen for: 14
Teach the new idea
Say this: “An array with 3 rows of 4 is 4 + 4 + 4 = 12.”
Say this: “Arrays are the doorway to multiplication next year.”
Say this: “Array: objects in equal rows and columns.”
Say this: “Repeated addition: adding the same number again and again.”
Show how
Show: 5 × 4 = ___
Say this: “5 groups of 4: 4 + 4 + 4 + 4 + 4 = 20”
Answer: 20
Show: Each of the 4 disciples carried 2 loaves. How many loaves did they carry?
$bar model$
Say this: “Unknown: the total.”
Say this: “Bar model: 4 equal parts of 2; the whole is unknown.”
Say this: “Equation: 4 × 2 = ?”
Say this: “4 × 2 = 8”
Say this: “Answer: They carried 8 loaves.”
Answer: 8 loaves. They carried 8 loaves.
Practice together
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: Write a multiplication fact for the array. How many in all?
$array of 2 rows and 3 columns$
Listen for: 2 × 3 = 6
If stuck: There are 2 rows of 3.
Ask: Write a multiplication fact for the array. How many in all?
$array of 4 rows and 3 columns$
Listen for: 4 × 3 = 12
If stuck: There are 4 rows of 3.
Ask: Write a multiplication fact for the array. How many in all?
$array of 3 rows and 3 columns$
Listen for: 3 × 3 = 9
If stuck: There are 3 rows of 3.
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
Watch for
- Adding the number of rows and columns.
Game: Array Hunt
Find arrays at home (egg cartons, window panes, muffin tins). Your child writes the repeated addition and the total for each.
Narration
Say this: “Tell me what you learned today. Show me with your hands or the counters if you like.”
Listen for: Write repeated addition for an array.
Daily habit
Skip count by 2s, 3s, 5s and 10s. Say: “3 rows of 4 make 12.”

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.