You will learn
- Read a word problem and decide to subtract.
- Find the start and the take-away number.
- Write and solve the sentence.
- Check that the answer makes sense.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Read the story. Find the numbers.
- Words like left, fewer and gave away tell us to subtract.
- Write the sentence: start number − take-away number.
- Check that the answer fits the story.
Words to know
A maths problem told as a story.
A word that helps, like left, fewer, gave away.
Find the answer.
Does it fit the story?
1. Discover: the story of the shop
“A shop has 14 notebooks. It sells 6 notebooks. How many notebooks are left?” What is the question asking?
2. Understand: subtraction word problems
1. Read the story. 2. Find the numbers (14 and 6). 3. Decide to subtract (clue: “sells”, “left”, “gave away”). 4. Write 14 − 6 = 8. 5. Check: 8 + 6 = 14.
Write the answer with the unit: 8 notebooks.
Idea 1: Find the start number and the take-away number
Ama has 15 beads. She gives away 6. The start number is 15. The take-away number is 6.
Idea 2: Clue words for taking away
Words like left, gave away, lost, fewer and flew away often mean subtract.
But think about the story. The clue words help, but the story decides.
Idea 3: Write, solve and check
Write 15 − 6 = 9. Check by adding: 9 + 6 = 15. The answer is smaller than 15, so it makes sense.
3. Worked examples
Example 1 (I show you): Eggs
There are 11 eggs. 4 break. How many eggs are not broken?
- Start number 11. Take-away number 4.
- Some break, so we subtract.
- 11 − 4 = 7.
Answer: 7 eggs are not broken.
Example 2 (We do it together): Beads
Ama has 15 beads. She gives away 6. How many are left?
- Start 15. Take away 6.
- 15 − 6 = 9.
Answer: 9 beads are left.
Example 3 (You try): Cats
9 cats are in a yard. 5 run away. How many cats are left?
Show the steps and answer
- Start 9. Take away 5.
- 9 − 5 = 4.
Answer: 4 cats are left.
Did you know?
Shopkeepers use subtraction to give change. If something costs 13 and you pay 20, the change is 20 − 13 = 7.
Why this matters
Stories about spending, sharing and losing need subtraction. The clue words help, but the story matters most.
4. Explore: act out the story
You need 15 counters.
- Read: “9 apples. 4 are eaten.” Make 9 counters.
- Take away 4.
- Count what is left.
- Write the sentence 9 − 4 = 5.
Think about it: what did you notice?
9 − 4 = 5 apples left.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- The start number is ___.
- I take away ___.
- The sentence is ___ − ___ = ___.
- My answer makes sense because ___.
Guided practice
Question 1. 10 birds, 3 fly away. Left?
10 − 3 = 7 birds.
Question 2. Which word is a clue to subtract: left or altogether?
left.
Question 3. 12 pens, 5 given away. Left?
12 − 5 = 7 pens.
Independent practice
Level 1: Start
- There are 11 eggs. 4 break. How many are not broken?
- Ama has 15 beads. She gives away 6. How many are left?
- 9 cats, 5 run away. How many cats are left?
- Make your own subtraction story for 10 − 7.
- Tom has 18 marbles. He loses 9. How many does he have?
Level 2: Grow
- There are 12 apples. 5 are eaten. How many are left?
- Kofi has 16 stickers. He gives away 7. How many are left?
- 13 birds are on a roof. 4 fly away. How many remain?
Level 3: Stretch
- Write your own subtraction story for 14 − 6.
- Ama has 15 beads. She loses 4, then loses 3. How many are left?
- A shop has 9 hats. It sells 12. Is that possible? Why not?
Answers are in the answer key below. Try first, then check.
6. Apply: everyday mathematics
A baker makes 16 buns and sells 9. How many buns are left?
Show a sample answer
16 − 9 = 7 buns.
Another one. You have 20 coins. You spend 8 coins. How many coins are left?
Show a sample answer
20 − 8 = 12 coins.
7. Common mistakes
Fix: Look for clue words and draw the story before you decide.
Fix: Think about the story. If something is taken away or lost, subtract.
Fix: The start number comes first: 15 − 6.
8. Lesson summary and revision card
- I can read a word problem and decide to subtract.
- I can find the start and the take-away number.
- I can write and solve the sentence.
- I can check that my answer makes sense.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Look for clue words like left and gave away.
- Write the subtraction sentence and solve.
- Check by adding back.
11. Next lesson
Next lesson: Grouping objects into tens. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- There are 14 pens. 6 are lost. How many pens are left? [2 marks]
- Write the words in this story that tell you to subtract: 9 birds, 4 fly away. [1 mark]
- Ama has 17 mangoes. She sells 8. Write the number sentence and the answer. [3 marks]
- Check that 15 − 9 = 6 using addition. [2 marks]
- Kofi says: I had 10 sweets, ate 4, so I have 14. Explain his mistake. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 14 − 6 [1] = 8 [1]
- fly away [1]
- 17 − 8 [1] = 9 [1]; sentence correct [1]
- 6 + 9 [1] = 15, so it is correct [1]
- He added instead of subtracting [1]; 10 − 4 = 6 [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- 11 − 4 = __
- 15 − 6 = __
- 9 − 5 = __
- 18 − 9 = __
- What clue word tells us to subtract?
- There are 9 eggs. 3 break. How many are left?
- Ana has 14 beads. She gives away 8. How many are left?
- Write the sentence for 12 balls when 5 are lost.
- Name one clue word for subtracting.
- How can you check 10 − 4 = 6?
Homework
Make up three subtraction stories about things at home. Write the number sentence for each and ask a family member to solve one.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 11 − 4 = __ | 7 | 2 |
| 15 − 6 = __ | 9 | 2 |
| 9 − 5 = __ | 4 | 2 |
| 18 − 9 = __ | 9 | 2 |
| What clue word tells us to subtract? | left | 2 |
| Total | 10 |
Practice answers: Worksheet: 1 7; 2 9; 3 4; 4 9; 5 left.
Quiz answers: 1 A, 2 B, 3 C, 4 A, 5 B, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 C, Challenge 2 C.
Extra worksheet answers (items 6 onward): 6 6; 7 6; 8 12 − 5 = 7; 9 left, gave away, fewer or lost; 10 6 + 4 = 10.
Independent practice answers. Level 1: 1 7; 2 9; 3 4; 4 a story such as: 10 mangoes, 7 are sold, 3 are left; 5 9. Level 2: 1 7; 2 9; 3 9. Level 3: 1 For example: 14 mangoes, 6 are sold, 8 are left.; 2 8; 3 No. You cannot sell more hats than you have..
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Read a word problem and decide to subtract | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Find the start and the take-away number | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Write and solve the sentence | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Check that the answer makes sense | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: Adding when the story says left or gave away. Look for clue words and draw the story before you decide.
- Explain another way: use real objects first, then pictures.
- Show a simpler example: Act out one story with counters and write the sentence together.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child solves simple take-away stories. You do not need to be good at mathematics to help.
- Make up stories at home: 8 biscuits, 3 are eaten.
- Ask: which number do we start with?
- Ask: does the answer make sense? It should be smaller than the start.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: read a word problem and decide to subtract; find the start and the take-away number; write and solve the sentence; check that the answer makes sense.
Prerequisite knowledge. Lessons 1 to 6.
Materials. Counters (stones, seeds or bottle tops), paper, pencils, board or chalkboard. Low-resource options: use stones, seeds, sticks, bottle tops or drawings in the sand or on the board instead of printed materials.
Preparation. Gather the counters and draw the example pictures on the board before the lesson.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Start with the Discover situation and let learners suggest ideas before you teach.
Explanation (10 min). Teach the Understand section with real objects first, then pictures, then symbols and words.
Guided activity (10 min). You need 15 counters. Learners follow the Explore steps in pairs.
Independent activity (10 min). Learners complete the independent practice and the worksheet.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. What is the start number? What is taken away? Does the answer fit the story?
Teacher explanation notes. Use the concrete, pictorial, abstract order: real objects first, then pictures, then symbols and words. Return to real objects whenever a learner needs support.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and work with a partner; say each step aloud together. Extension. Ask learners to make up their own example and explain it to a partner.
Formative assessment. Listen to learner explanations, ask “how do you know?”, and check the independent work.
Misconceptions. Adding when the story says left or gave away. Look for clue words and draw the story before you decide.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz and worksheet on this page. The 10-mark exam practice scheme, the 10-mark scheme and all answers are in the answer sections above. Re-check every answer and the marking scheme before publication.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Act out one story with counters and write the sentence together. Enrichment. Invite learners to find or create three more examples at home or in the classroom and explain them. Homework. See above.
Teacher reflection. After teaching, record: which concepts learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points named in the Courseversity standard: Common Core State Standards for Mathematics, Cambridge Primary and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Official standards for this topic area. Common Core State Standards for Mathematics (official site): Grade 1 » Operations & Algebraic Thinking; Grade 1 » Number & Operations in Base Ten. These pages list the standards that cover this topic area; read them alongside the lesson.
Research used to shape this lesson. Common Core 1.OA.A.1 (subtraction word problems within 20); Cambridge Primary Mathematics Stage 1. These sources informed the lesson.