CBSE Class 1 · Mathematics
Lina's Family (Measurement)
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 “Lina's Family (Measurement)” 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
1Taller and shorter by standing next to each other
Taller is the head that ends higher when two people stand on the same floor. Shorter is the other head.
A number is not required. The compare is a stand-next-to test.
Figure. Taller is the head that ends higher when both people stand on the same floor. A stool cheats the test.
How it works
- Stand on the same floorDo not put one on a stool.
- Look at the two headsWhich ends higher?
- Name taller or shorterThat is the compare.
2A family line-up is an order, not a numeral yet
Shortest to tallest is an order. You can make that line before anyone has a height in centimetres.
Swapping two people breaks the order even if you never wrote a number.
Figure. Shortest to tallest is an order you can make before anyone has a height in centimetres. Each next neighbour must be taller.
How it works
- Pick a ruleShortest to tallest.
- Place each person onceNo one twice.
- Check neighboursEach next person is taller.
3A bottle, spoon, or pencil can be a repeating unit
A unit is something you can lay end to end without gaps. A bottle, a spoon, or a pencil can be that unit.
Hands of different sizes are a poor unit — they do not stay the same.
Figure. A unit is laid end to end with no gap and no overlap. The count of those equal units is the measure.
How it works
- Pick one unitThe same pencil every time.
- Lay it end to endNo gap, no overlap.
- Count how many unitsThat count is the measure.
4The unit must stay the same mid-measure
Start with a pencil, finish with a pencil. Switching to a bottle mid-way makes the count mute.
The number only speaks if every unit was the same size.
Figure. Start with a pencil, finish with a pencil. A bottle swapped in mid-count makes the number mute.
How it works
- Name the unit at the startPencil.
- Refuse a swapNo bottle halfway.
- Finish with the same unitThen the count is honest.
5A number without a unit is mute
“The mat is 6” does not say 6 what. Six pencils and six bottles are different lengths.
Always say the unit after the number.
Figure. Six by itself does not say six what. Six pencils and six bottles are different lengths.
How it works
- Write the count6.
- Write the unitPencils.
- Read both6 pencils, not 6.
Which measure is honest?
- The desk is 8 pencils
- The desk is 8
- The desk is tall
A number without a unit is mute.
6Heavier and lighter on a compare, then a unit
A pan balance tells heavier and lighter before anyone names kilograms. The compare comes first.
A unit (the same block, again and again) can wait until the compare is clear.
Figure. The pan that goes down is heavier. Kilograms can wait until this compare is clear.
How it works
- Put one object on each panSame hook, two sides.
- See which side goes downThat side is heavier.
- Name heavier or lighterA kilogram can wait.
7Holds more or holds less
A jug holds more than a cup if the cup’s water fits in the jug with room left. That is a fill-test.
A tall thin bottle can hold less than a short wide one. Height is not the test.
Figure. The jug holds more if the cup’s water fits and room remains. Height alone is not the test.
How it works
- Fill the smallerA cup.
- Pour into the largerA jug.
- Ask if room remainsRoom left means the jug holds more.
8Estimate before you count units
Guess “about 6 pencils” before you lay them. Then measure. The guess trains the eye; the count is the honest measure.
A guess that you never check is not a measure.
Figure. Guess first to train the eye. Then lay the units. The count, not the guess, is the measure.
How it works
- Look firstSay an about-number.
- Lay the unitEnd to end.
- Compare guess and countThe count wins.
Notes
- The official chapter title is “Lina's Family (Measurement)”. 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 “Lina's Family (Measurement)”. The wording is ExamMaster’s teaching, not a textbook recap.
- Taller and shorter by standing next to each other
- Taller is the head that ends higher when two people stand on the same floor.
- A family line-up is an order, not a numeral yet
- Shortest to tallest is an order. You can make that line before anyone has a height in centimetres.
- A bottle, spoon, or pencil can be a repeating unit
- A unit is something you can lay end to end without gaps.
- The unit must stay the same mid-measure
- Start with a pencil, finish with a pencil.
- A number without a unit is mute
- “The mat is 6” does not say 6 what. Six pencils and six bottles are different lengths.
- Heavier and lighter on a compare, then a unit
- A pan balance tells heavier and lighter before anyone names kilograms.
Practise Lina's Family (Measurement)
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