Parent guide · Grade 1 Math · Unit 3
Lesson 3.1 Counting Back
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
- Subtract 1, 2 or 3 by counting back.
- You need
- Pencil and crayons
- A King James Bible
- Worksheet A · Worksheet B · the lesson page
Steps
Do this: Ask these out loud. Your child answers out loud; no paper needed.
- Ask: “9 − 6” Listen for: 3
- Ask: “15 − 0” Listen for: 15
- Ask: “7 − 1” Listen for: 6
- Ask: “13 − 5” Listen for: 8
- Ask: “11 − 2” Listen for: 9
Say this: “To take away a small number, start at the big number and count back.”
Say this: “12 − 3: 11, 10, 9.”
Say this: “Count back: say numbers going down.”
Show: 19 − 1 = ___
Say this: “Start at 19 and count back 1: 18.”
Say this: “19 − 1 = 18”
Answer: 18
Show: The orchard had 11 apples on a tree. The children picked 4. How many apples are left on the tree?
Say this: “Unknown: how many are left.”
Say this: “Bar model: the whole is 11; one part is 4; the other part is unknown.”
Say this: “Equation: 11 − 4 = ?”
Say this: “11 − 4 = 7”
Say this: “Answer: 7 apples are left.”
Answer: 7 apples. 7 apples are left.
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: 7 − 2 = ___
Listen for: 5
If stuck: Start at 7 and count back 2: 6, 5.
Ask: 8 − 2 = ___
Listen for: 6
If stuck: Start at 8 and count back 2: 7, 6.
Ask: 8 − 1 = ___
Listen for: 7
If stuck: Start at 8 and count back 1: 7.
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
- Saying the starting number as the first count.
Draw a house with three numbers in the roof (like 6, 8, 14). Your child writes all four facts in the windows. Score a point for each correct fact.
Say this: “Tell me what you learned today. Show me with your hands or the counters if you like.”
Listen for: Subtract 1, 2 or 3 by counting back.
What man of you, having an hundred sheep, if he lose one of them, doth not leave the ninety and nine in the wilderness, and go after that which is lost, until he find it?
100 − 1 = 99. The shepherd knew one was missing and went to find it.
Count back from 20 by ones and by twos. Say the subtraction partners of 10 (10 − 1 = 9 …).
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.