CBSE Class 1 · Mathematics
Making 10 (Numbers 10 to 20)
Official NCERT chapter from Joyful Mathematics (English) (book code aejm1). ExamMaster notes are original teaching at CBSE Class 1 depth.
This lesson follows the official chapter “Making 10 (Numbers 10 to 20)” in Joyful Mathematics (English). The words below are ExamMaster’s teaching, not a paste from the book. Use the NCERT chapter for the classroom sequence; use these notes to hold the idea without copying exercises or figures.
- CBSE Class 1
- Easy level
- 8 concepts
1Dots on a bug are a count you can point to
Each dot on the bug is one. Point, then say the word. The picture is a count, not a decoration.
If you cannot point to a dot, do not give it a word.
Figure. A count is a pointing. Each box is one dot. Seven is the last name you say, not a new kind of number.
How it works
- Point to a dotOne word.
- Finish every dotNo skip, no double.
- Keep the last wordThat is how many dots.
2Ten is a finished bundle of ones
Ten ones make one ten. That bundle is a new house, not a prettier 1.
You may still count them as ones. The bundle is a faster name for the same group.
Figure. Ten ones finish a bundle. The bundle is one ten, not “1 and 0” as two ones.
How it works
- Count ten onesOne-to-one to ten.
- Bundle themThat bundle is 1 ten.
- Do not call it “just 1”The house is tens, not ones.
3A ten-frame shows how many still hide to make 10
A ten-frame has ten seats. Filled seats are the count you have. Empty seats are how many still hide to make 10.
6 filled means 4 empty. That is a split of the same ten, not a new number.
Figure. A ten-frame has ten equal seats. Six filled leaves four still hiding to make 10.
How it works
- Count the filledThose are the ones you have.
- Count the emptyThose hide to make 10.
- Check the total seatsFilled plus empty is 10.
Empty seats on a ten-frame
6 seats are filled. How many still hide to make 10?
- Filled6
- Ten seats10
- Empty10 - 6 = 4
Pro tip. Filled plus empty must be ten.
4Vanishing buttons is a take-away from ten
Ten buttons, three vanish. Seven remain. The story is take-away, not a new total from nowhere.
Joining the three back must rebuild ten. That check earns the subtraction.
Figure. Vanishing buttons are a take-away from ten. Three empty seats are the 3 that left; seven remain.
How it works
- Start at 10A finished bundle.
- Take 3 awayPoint at the ones that leave.
- Name what remains7. Check: 7 + 3 = 10.
Buttons from ten
10 buttons. 3 vanish. How many remain?
- Start10
- Take 310 - 3
- Remain7
Pro tip. Join back to check: 7 + 3 = 10.
511 to 20 are ten and some leftover ones
14 is one ten and four leftover ones. It is not “1 and 4” as two ones.
The leftover ones sit in the ones house. The ten sits in the tens house.
Figure. Teens are a finished ten plus leftover ones. 14 is not “1 and 4” as two ones.
How it works
- See the tenOne finished bundle.
- Count the leftoversThose are the ones.
- Read both houses“Ten and four” is fourteen.
6Compare teens by the leftover ones
16 and 19 share one ten. Compare the leftover ones: 6 and 9. 19 is more.
Do not compare the tens house — both have one ten. The ones house decides.
Figure. Both teens share a ten. Compare the leftover ones: 7 leftover beats 3 leftover, so 17 is more.
How it works
- Check the tensSame one ten?
- Compare the onesWhich leftover is more?
- Name the larger teenThe one with more leftover ones.
7Twenty is two tens
Twenty is two finished bundles of ten, not “two and zero” as two ones.
The zero holds the ones house open so the 2 can sit in tens.
Figure. Twenty is two finished tens. It is not “2 and 0” as two ones.
How it works
- Make one tenA bundle of ten ones.
- Make a second tenAnother bundle.
- Read 20Two tens, zero leftover ones.
8Making ten is a split of the same total
10 can be 7 and 3 or 6 and 4. The total stayed; the split changed.
If a split no longer adds to ten, it is a different number, not a clever rewrite.
Figure. Making ten is a split of one total. 6 and 4 are partners of the same 10, not two new numbers.
How it works
- Fix the totalKeep ten in mind.
- Move one from a partThe other part must compensate.
- Check the totalIf it moved, the split is wrong.
7 and 3 make 10. 6 and which number still make 10?
- 4
- 3
- 7
Move one from 7 to the other part: 6 and 4.
Notes
- The official chapter title is “Making 10 (Numbers 10 to 20)”. Teach the school test for that title, not a contest shortcut.
- If a step needs a later class, stop. The next official chapter will pick it up.
Formulas
- 10 = 7 + 3 = 6 + 4 (same total, new split)
- A teen is 10 + leftover ones.
Reference tables
The total stays ten. Only the split changes.
| One part | Other part | Total |
|---|---|---|
| 7 | 3 | 10 |
| 6 | 4 | 10 |
| 5 | 5 | 10 |
| 8 | 2 | 10 |
Recap
Hold these pegs from the official chapter “Making 10 (Numbers 10 to 20)”. The wording is ExamMaster’s teaching, not a textbook recap.
- Dots on a bug are a count you can point to
- Each dot on the bug is one. Point, then say the word. The picture is a count, not a decoration.
- Ten is a finished bundle of ones
- Ten ones make one ten. That bundle is a new house, not a prettier 1.
- A ten-frame shows how many still hide to make 10
- A ten-frame has ten seats. Filled seats are the count you have. Empty seats are how many still hide to make 10.
- Vanishing buttons is a take-away from ten
- Ten buttons, three vanish. Seven remain. The story is take-away, not a new total from nowhere.
- 11 to 20 are ten and some leftover ones
- 14 is one ten and four leftover ones. It is not “1 and 4” as two ones.
- Compare teens by the leftover ones
- 16 and 19 share one ten. Compare the leftover ones: 6 and 9. 19 is more.
Practise Making 10 (Numbers 10 to 20)
Reading is free and needs no account. Practice, mocks and progress live in the app.
- A 4-question practice set that ends the chapter
- 1 quick check with worked explanations
- Timed mocks scored with the real marking scheme
- Readiness tracked per topic, kept on your device