CBSE Class 4 · Mathematics
Pattern Around Us
Official NCERT chapter from Math-Mela (book code demm1). ExamMaster notes are original teaching at CBSE Class 4 depth.
This lesson follows the official chapter “Pattern Around Us” in Math-Mela. 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 4
- Easy level
- 8 concepts
1Coconut trees in a line can hide a repeating unit
A line of trees is a pattern only if a chunk repeats: tall-short-tall-short, or 2-then-1. The unit is that chunk.
A line with no repeating chunk is just a list.
Figure. A line of coconut trees can hide a two-step unit: tall then short. Once that chunk is marked, the rest of the line is the same chunk again — not six separate guesses.
How it works
- Walk the lineLook for a chunk that restarts.
- Name the unitThe smallest chunk that repeats.
- Check the next treesSame unit, or a break.
2Let us count: the unit must restart honestly
After one unit ends, the next must start the same way. Counting “1, 2, 3” of a 2-chunk is a broken restart.
Honest restart means the first piece of the unit comes back.
Figure. Counting the pattern means counting how many times the unit starts again. Here the unit is two trees, so six trees are three restarts — not six new units.
How it works
- Mark the end of a unitLast piece of the chunk.
- See the next pieceIs it the unit’s first piece?
- If not, the pattern brokeDo not force the count.
3Predict the next tree or tile from the unit
If the unit is A-B-A-B, the next after B is A. Prediction is the unit, not a favourite tree.
Guessing a new colour because it looks nice is not a prediction.
Figure. Name the unit first, then fill the empty place. Tall-short has used five marks, so the last used mark is tall and the empty place must be short. Guessing without the unit is luck.
How it works
- Hold the unitA-B.
- See what just endedB.
- Say the next pieceA.
Next tile from a unit
Tiles go red, blue, red, blue, red. What colour is the next tile if the unit is red-blue?
- Unitred-blue
- Last tilered
- Nextblue
Pro tip. The unit restarts after each blue. After a red, blue is due.
4A growing pattern adds a piece each time
1 tree, then 2, then 3 is a growing pattern: each term adds one. The rule is “add one each time”, not a repeating A-B.
Do not call a growing pattern a repeating unit of two.
Figure. A growing pattern is not a restart of the same chunk. Row 1 has one tile, row 2 has two, row 3 has three, row 4 has four — each row adds one new tile to the previous row.
How it works
- See how the next term changesAdds a piece?
- Name the add-on+1 tree, or +1 tile.
- Predict with that add-onNot with a fake A-B.
5Colour or shape can be the chunk
The unit can be colours, or shapes, or both. Name which property is repeating before you predict.
Mixing an unspoken colour-unit with a shape-unit is two patterns mashed.
Figure. The repeating piece can be a colour change or a shape change. A-B-C is a three-step colour unit; wide-tall is a two-step shape unit. Name which property is repeating before you predict the next mark.
How it works
- Pick the propertyColour, or shape.
- Name the unit in that propertyRed-blue, or square-circle.
- Predict in that property onlyDo not swap mid-line.
6Copy the unit onto a new row to check
The next row must reuse the same unit. A new doodle means the pattern broke.
Checking is copying, not admiring.
Figure. To check a unit, copy it onto a new row. If the new row matches the old row mark for mark, the unit was honest. A leftover sliver or a swapped mark means you marked the wrong chunk.
How it works
- Hold the unitFrom row 1.
- Place it on row 2Same size, same order.
- If it fails, fix the copyDo not rename the failure a style.
7A broken chunk is a new pattern
If A-B-A-B becomes A-B-C, you do not still have A-B. Name the new unit or say the pattern stopped.
Forcing the old unit onto a C is a lie.
Figure. A-B-A-B-A was the unit restarting. The last mark is C, so the chunk broke. Do not force C into the old unit — the line has become a different pattern from that mark on.
How it works
- See the unexpected pieceC.
- Ask: new unit, or a stop?Evidence only.
- Do not paste the old unit over itBroken is broken.
8Almost the same is not the same unit
Red-blue-red-green is not “almost A-B”. Almost is a miss.
The unit is exact or it is not the unit.
Figure. A-B-A and A-B-B look almost the same — two marks match. The third mark does not, so they are not the same unit. Almost is a fail on the fold-or-repeat test.
How it works
- Write the claimed unitRed-blue.
- Compare to what is thereRed-blue-red-green.
- If a piece differs, reject the claimNot the same unit.
A growing pattern 1, 2, 3 trees is
- Add one each time, not a repeating A-B of two
- The unit red-blue
- A broken colour
Growing adds a piece; repeating restarts a chunk.
Notes
- The official chapter title is “Pattern Around Us”. 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
- Next term = next piece of the named unit (or + the growing add-on).
Recap
Hold these pegs from the official chapter “Pattern Around Us”. The wording is ExamMaster’s teaching, not a textbook recap.
- Coconut trees in a line can hide a repeating unit
- A line of trees is a pattern only if a chunk repeats: tall-short-tall-short, or 2-then-1.
- Let us count: the unit must restart honestly
- After one unit ends, the next must start the same way.
- Predict the next tree or tile from the unit
- If the unit is A-B-A-B, the next after B is A.
- A growing pattern adds a piece each time
- 1 tree, then 2, then 3 is a growing pattern: each term adds one.
- Colour or shape can be the chunk
- The unit can be colours, or shapes, or both.
- Copy the unit onto a new row to check
- The next row must reuse the same unit. A new doodle means the pattern broke.
Practise Pattern Around Us
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