CBSE Class 1 · Mathematics
What is Long? What is Round? (Shapes)
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 “What is Long? What is Round? (Shapes)” 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
1Long names one stretch; round names a closed curve
Long is a stretch you can run a finger along. Round is a closed curve that comes back to the start.
A pencil is long. A bangle is round. Those are two different feel-tests, not two colours.
Figure. Long is one stretch you can run a finger along. Round here means a closed path that returns to the start — drawn as a closed rectangle because this renderer has no arc.
How it works
- Try a stretchFinger along the object.
- Try a closed curveDoes the path come back?
- Keep one name per testDo not mix long with red.
2The same object can be long in one way and round in another
A glass is tall (a long stretch from the side) and round on the rim. One object, two tests.
The object did not change. The test did. That is why we name the test, not “the one true shape”.
Figure. The glass did not change. The side test is a long stretch; the top test is a closed rim. The compact square is a rim token, not a drawn circle.
How it works
- Fix the objectDo not swap the glass.
- Change only the testSide stretch, then rim.
- Allow two namesLong from the side; round on the rim.
3Sort objects that behave the same: roll or stay
A ball rolls every way. A box stays unless you tip it. The motion is the evidence.
Sort by that motion before you pin on a school name like sphere or cuboid.
Figure. Sort by what the object does. A ball rolls; a box stays unless you tip it. Square tokens stand for the objects — the test is the motion, not a painted circle.
How it works
- Pick one objectBall, box, or coin.
- Try one motionRoll, or stay.
- Group the same moversSame motion, same sort.
4A slide needs a long path
A box slides on a flat face along a path. If there is no long path, it is not a slide test.
Rolling on an edge is a different motion. Do not call every move a slide.
Figure. A slide needs a flat face and a long path. Push without tipping. Rolling on an edge is a different test.
How it works
- Find a flat faceThe face that can rest.
- Give it a pathA table or a board.
- Push without tippingThat is the slide.
6A ball is round every way; a box is not
Turn a ball — every view is still a closed curve. Turn a box — you meet a flat face and a corner.
“Round every way” is the ball’s test. One round face on a tin is not the same test.
Figure. Turn a ball: the feel stays. Turn a box: a new face or corner appears. Tokens are the same size on the ball side on purpose. One round face on a tin is not this test.
How it works
- Turn the objectKeep turning.
- Ask if the feel staysStill no corner?
- Name only after the turnBall, or box.
7A top view can look round when the object is a glass
From above a glass looks like a circle. From the side it looks taller. The glass did not change.
Drawing the top view as if it were the whole object is the usual mix-up. Ask: where was the eye?
Figure. From above the outline is squat; from the side it is tall. The glass stayed. Drawing the top view as the whole object is the usual mix-up.
How it works
- Fix the glassDo not turn it while you move.
- Change only the eyeTop, then side.
- Compare outlinesDifferent outline, same glass.
8Keep the school name after the feel-test
Sphere, cuboid, and circle are school names we pin on after the test. The test comes first.
Saying the name before you roll or slide is a label with no job.
Figure. Sphere and cuboid are pins after the test. A name with no roll or slide is a label with no job. The dashed skip is the trap.
How it works
- Run the testRoll, slide, or look from two places.
- Group the same testersSame evidence, same sort.
- Then pin the school nameOnly now the name is earned.
Notes
- The official chapter title is “What is Long? What is Round? (Shapes)”. 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.
Recap
Hold these pegs from the official chapter “What is Long? What is Round? (Shapes)”. The wording is ExamMaster’s teaching, not a textbook recap.
- Long names one stretch; round names a closed curve
- Long is a stretch you can run a finger along.
- The same object can be long in one way and round in another
- A glass is tall (a long stretch from the side) and round on the rim.
- Sort objects that behave the same: roll or stay
- A ball rolls every way. A box stays unless you tip it. The motion is the evidence.
- A slide needs a long path
- A box slides on a flat face along a path. If there is no long path, it is not a slide test.
- Match objects that share a shape, not a colour
- A red ball and a blue ball share the roll-test.
- A ball is round every way; a box is not
- Turn a ball — every view is still a closed curve.
Practise What is Long? What is Round? (Shapes)
Reading is free and needs no account. Practice, mocks and progress live in the app.
- A 4-question practice set that ends the chapter
- Timed mocks scored with the real marking scheme
- Readiness tracked per topic, kept on your device