CBSE Class 3 Mathematics Revision Worksheet Set 08

Q.1 Fill in the blanks.

Question (1). 5m = _____________ cm.
Answer: 500
In simple words: Since 1 m = 100 cm, multiply 5 by 100 to get 500 cm.

Exam Tip: Always remember the conversion factor: \(1\text{ m} = 100\text{ cm}\).

Question (2). 12 inches make _____________ foot.
Answer: 1
In simple words: 12 inches is equal to 1 foot.

Exam Tip: 1 foot equals 12 inches.

Question (3). 1 yard = ______________ feet.
Answer: 3
In simple words: One yard is equal to 3 feet.

Question (4). 1 cm = _____________ mm.
Answer: 10
In simple words: 1 centimetre has 10 millimetres.

Exam Tip: \(1\text{ cm} = 10\text{ mm}\).

Question (5). 9000 m = _____________ km.
Answer: 9
In simple words: Divide 9000 by 1000 since \(1000\text{ m} = 1\text{ km}\).

Exam Tip: To convert metres to kilometres, divide by 1000.

Question (6). \(7\text{ m} \times \text{_____________} = 56\text{ m}\).
Answer: 8
In simple words: Find what number multiplied by 7 gives 56, which is 8.

Exam Tip: Use basic multiplication tables: \(7 \times 8 = 56\).

Question (7). \(42000 \div 1000 = \text{___________} \text{ km}\).
Answer: 42
In simple words: Cancel three zeros from 42000 to get 42.
Exam Tip: Dividing by 1000 shifts the decimal point three places to the left.

Question (8). 8 Km 525 m ____________ 85 m 25 cm (put < , >)
Answer: >
In simple words: 8 kilometres and 525 metres is much larger than 85 metres and 25 centimetres.

Exam Tip: Compare the larger units (kilometers vs metres) first.

Question (9). The standard unit for measuring length is called ____________ .
Answer: metre
In simple words: The basic SI unit of length is the metre.

Exam Tip: Remember that the metre is the standard unit of length.

Question (10). The ___________ of a figure is the region enclosed within its boundary.
Answer: area
In simple words: The space inside a closed boundary is called area.

Exam Tip: Distinguish between perimeter (boundary) and area (enclosed region).

Question (11). __________ and ___________ are non standard units.
Answer: Handspan, Cubit (or Pace, Footspan)
In simple words: Units that change from person to person, like handspan, are non-standard.

Exam Tip: Non-standard units are not fixed universally.

Q.2 Convert the following lengths. (Show calculation)

Question (1). \(2508\text{ m} = \text{________} \text{ km} \text{ _________} \text{ m}\)
Answer: 2 km 508 m
Calculation:
\(2508\text{ m} = 2000\text{ m} + 508\text{ m}\)
Since \(1000\text{ m} = 1\text{ km}\), \(2000\text{ m} = 2\text{ km}\)
So, \(2508\text{ m} = 2\text{ km } 508\text{ m}\)
In simple words: Separate the thousands place for kilometres and the remaining for metres.

Exam Tip: Split the number into a multiple of 1000 and the remainder.

Question (2). \(98\text{ m } 5\text{ cm} = \text{__________} \text{ cm}\)
Answer: 9805 cm
Calculation:
\(1\text{ m} = 100\text{ cm}\)
\(98\text{ m} = 98 \times 100\text{ cm} = 9800\text{ cm}\)
\(9800\text{ cm} + 5\text{ cm} = 9805\text{ cm}\)
In simple words: Convert metres to centimetres by multiplying by 100 and add 5 cm.

Exam Tip: Multiply metres by 100, then add the centimetres.

Question (3). \(84\text{ km } 6\text{ m} = \text{__________} \text{ m}\)
Answer: 84006 m
Calculation:
\(1\text{ km} = 1000\text{ m}\)
\(84\text{ km} = 84 \times 1000\text{ m} = 84000\text{ m}\)
\(84000\text{ m} + 6\text{ m} = 84006\text{ m}\)
In simple words: Multiply kilometres by 1000 and add 6 metres (note: 6 m is written as 006 m).

Exam Tip: Ensure proper place value alignment; 6 m is 006 when adding to thousands.

Question (4). \(6723\text{ cm} = \text{________} \text{ m} \text{ _______} \text{ cm}\)
Answer: 67 m 23 cm
Calculation:
\(6723\text{ cm} = 6700\text{ cm} + 23\text{ cm}\)
Since \(100\text{ cm} = 1\text{ m}\), \(6700\text{ cm} = 67\text{ m}\)
So, \(6723\text{ cm} = 67\text{ m } 23\text{ cm}\)
In simple words: The last two digits give centimetres and the rest give metres.

Exam Tip: Divide by 100: quotient is metres, remainder is centimetres.

Q.3 Add the following lengths.

Question (1). Add 7 km 008 m and 9 km 236 m
Answer: 16 km 244 m
Calculation:
Metres: \(8 + 236 = 244\text{ m}\)
Kilometres: \(7 + 9 = 16\text{ km}\)
Sum = \(16\text{ km } 244\text{ m}\)
In simple words: Add metres separately and kilometres separately.

Exam Tip: Always add smaller units first.

Question (2). Add 432 m 67 cm and 9 m 48 cm
Answer: 442 m 15 cm
Calculation:
Centimetres: \(67 + 48 = 115\text{ cm} = 1\text{ m } 15\text{ cm}\)
Metres: \(432 + 9 + 1\text{ (carry)} = 442\text{ m}\)
Sum = \(442\text{ m } 15\text{ cm}\)
In simple words: Add cm, carry over 1 m when it exceeds 100 cm, then add m.

Exam Tip: 100 cm = 1 m, so carry over 1 to the metre column.

Question (3). Add 72 m 18 cm and 99 m
Answer: 171 m 18 cm
Calculation:
Centimetres: \(18 + 00 = 18\text{ cm}\)
Metres: \(72 + 99 = 171\text{ m}\)
Sum = \(171\text{ m } 18\text{ cm}\)
In simple words: Add the metres together and keep the 18 cm as it is.

Exam Tip: Align decimal or unit columns correctly before adding.

Q.4 Subtract the following lengths.

Question (1). Subtract 2 km 942 m from 9 km 568 m
Answer: 6 km 626 m
Calculation:
Metres: \(568 - 942\) (Borrow 1 km = 1000 m from 9)
New metres: \(1568 - 942 = 626\text{ m}\)
Kilometres: \(8 - 2 = 6\text{ km}\)
Difference = \(6\text{ km } 626\text{ m}\)
In simple words: Borrow 1 km (1000 m) if the top metre is smaller than the bottom metre.

Exam Tip: Check if borrowing is needed in the lower unit column.

Question (2). Subtract 5 km 234 cm from 7 km 486 cm
Answer: 2 km 252 cm
Calculation:
Centimetres: \(486 - 234 = 252\text{ cm}\)
Kilometres: \(7 - 5 = 2\text{ km}\)
Difference = \(2\text{ km } 252\text{ cm}\)
In simple words: Subtract centimeters and kilometers directly as no borrowing is needed.

Exam Tip: Verify units match carefully before subtracting.

Question (3). Subtract 28 m 62 cm from 84 m 00 cm
Answer: 55 m 38 cm
Calculation:
Centimetres: \(00 - 62\) (Borrow 1 m = 100 cm from 84)
New cm: \(100 - 62 = 38\text{ cm}\)
Metres: \(83 - 28 = 55\text{ m}\)
Difference = \(55\text{ m } 38\text{ cm}\)
In simple words: Borrow 1 m as 100 cm to subtract 62 cm from 00 cm.

Exam Tip: Borrowing across zero requires changing 00 to 100 and reducing the metre by 1.

Question (5)(1). Rama's height is 1 m 25 cm. If Rama is 29 cm taller than Rimi, what is Rimi's height?
Answer: 0 m 96 cm (or 96 cm)
Calculation:
Rama's height = \(1\text{ m } 25\text{ cm} = 100\text{ cm} + 25\text{ cm} = 125\text{ cm}\)
Rimi's height = Rama's height - 29 cm
\(125\text{ cm} - 29\text{ cm} = 96\text{ cm}\)
In simple words: Subtract 29 cm from Rama's total height in centimetres.

Exam Tip: Convert mixed units into a single smaller unit (cm) to make subtraction easier.

Question (5)(2). A 5 m 5 cm long ribbon is cut into 5 equal parts. How long is each part?
Answer: 1 m 1 cm
Calculation:
Total length = \(5\text{ m } 5\text{ cm} = 505\text{ cm}\)
Number of parts = 5
Length of each part = \(505\text{ cm} \div 5 = 101\text{ cm} = 1\text{ m } 1\text{ cm}\)
In simple words: Convert the total length to cm, divide by 5, and convert back.

Exam Tip: Division is easier when all quantities are in the same unit.

Practice Worksheet-II

Q.1 Write true or false.

Question (1). \(50\text{ km} = 5000\text{ m}\).
Answer: False
In simple words: 50 km is equal to \(50,000\text{ m}\), not 5000 m.

Exam Tip: Multiply by 1000, so 50 km = 50,000 m.

Question (2). \(8\text{ m } 6\text{ cm} = 860\text{ cm}\).
Answer: False
In simple words: 8 m 6 cm = 806 cm, because 6 cm is written as 06.

Exam Tip: 8 m = 800 cm, plus 6 cm = 806 cm.

Question (3). \(2489\text{ m} = 2\text{ km } 489\text{ m}\).
Answer: True
In simple words: 2000 m makes 2 km, leaving 489 m.

Exam Tip: Correct separation of thousands and remainder.

Question (4). \(700\text{ cm} = 7\text{ m}\).
Answer: True
In simple words: Dividing 700 by 100 gives 7.

Exam Tip: \(100\text{ cm} = 1\text{ m}\).

Question (5). To measure greater distances, we use the unit kilometre.
Answer: True
In simple words: Kilometre is used for long distances like city-to-city travel.

Exam Tip: Kilometre is the standard large unit of length.

Question (6). \(7\text{ km } 5\text{ m} = 705\text{ m}\).
Answer: False
In simple words: 7 km 5 m = 7005 m.

Exam Tip: Do not miss place holders: 7 km = 7000 m.

Q.2 Add the following with conversion.

Question (1). Add 8 km 600 m and 750 m
Answer: 9 km 350 m
Calculation:
\(8\text{ km } 600\text{ m} = 8600\text{ m}\)
\(+ 750\text{ m} = 750\text{ m}\)
Total = \(9350\text{ m} = 9\text{ km } 350\text{ m}\)
In simple words: Convert all to metres, add, and convert back to km and m.

Exam Tip: Total metres exceeding 1000 are converted back to kilometres.

Question (2). Add 68 m 24 cm and 5 m 7 cm
Answer: 73 m 31 cm
Calculation:
\(68\text{ m } 24\text{ cm} = 6824\text{ cm}\)
\(+ 5\text{ m } 7\text{ cm} = 507\text{ cm}\)
Total = \(7331\text{ cm} = 73\text{ m } 31\text{ cm}\)
In simple words: Convert both to centimetres, add them, and convert back to metres and centimetres.

Exam Tip: \(5\text{ m } 7\text{ cm}\) equals 507 cm, not 57 cm.

Q.3 Subtract the following with conversion.

Question (1). Subtract 3 km 806 m from 9 km
Answer: 5 km 194 m
Calculation:
\(9\text{ km} = 9000\text{ m}\)
\(- 3\text{ km } 806\text{ m} = 3806\text{ m}\)
\(9000 - 3806 = 5194\text{ m} = 5\text{ km } 194\text{ m}\)
In simple words: Convert 9 km to 9000 m and subtract 3806 m.

Exam Tip: Converting to the smaller unit avoids complex borrowing.

Question (2). Subtract 36 cm from 83 m 54 cm
Answer: 83 m 18 cm
Calculation:
\(83\text{ m } 54\text{ cm} = 8354\text{ cm}\)
\(- 36\text{ cm} = 36\text{ cm}\)
\(8354 - 36 = 8318\text{ cm} = 83\text{ m } 18\text{ cm}\)
In simple words: Subtract 36 cm from the 54 cm part.

Exam Tip: Only the centimetre part changes.

Q.4 Multiply the following.

Question (1). Multiply 624 m by 2
Answer: 1248 m (1 km 248 m)
Calculation:
\(624 \times 2 = 1248\text{ m}\)
In simple words: Multiply 624 by 2 to get 1248 metres.

Exam Tip: Multiplication works just like standard whole numbers.

Question (2). Multiply 4 m 23 cm by 8
Answer: 33 m 84 cm
Calculation:
\(4\text{ m} \times 8 = 32\text{ m}\)
\(23\text{ cm} \times 8 = 184\text{ cm} = 1\text{ m } 84\text{ cm}\)
Total metres = \(32 + 1 = 33\text{ m}\)
Total = \(33\text{ m } 84\text{ cm}\)
In simple words: Multiply metres and centimetres separately, then carry over excess centimetres.

Exam Tip: Always convert excess centimetres into metres before final writing.

Question (3). Multiply 9 km 304 m by 9
Answer: 83 km 736 m
Calculation:
\(9\text{ km} \times 9 = 81\text{ km}\)
\(304\text{ m} \times 9 = 2736\text{ m} = 2\text{ km } 736\text{ m}\)
Total km = \(81 + 2 = 83\text{ km}\)
Total = \(83\text{ km } 736\text{ m}\)
In simple words: Multiply km and m by 9 and convert excess metres to km.

Exam Tip: \(2736\text{ m}\) gives 2 km and 736 m.

Q.5 Write 'm' for metre or 'cm' for centimetre or 'km' for kilometre accordingly.

Question (1). The length of a boat. ________
Answer: m
In simple words: Boats are large, so they are measured in metres.

Exam Tip: Choose metres for medium-sized objects.

Question (2). The length of a toothbrush. ________
Answer: cm
In simple words: Toothbrushes are small, measured in centimetres.

Exam Tip: Choose cm for small objects.

Question (3). The distance between Vadodara to Surat. ________
Answer: km
In simple words: Distances between cities are measured in kilometres.

Exam Tip: Use km for long inter-city distances.

Question (4). The height of a building. ________
Answer: m
In simple words: Buildings are tall, so height is measured in metres.

Exam Tip: Heights of buildings use metres.

Question (5). The length of a saree. ________
Answer: m
In simple words: Sarees are long fabric lengths, measured in metres.

Exam Tip: Cloth length is typically in metres.

Question (6). The length of Slipper. ________
Answer: cm
In simple words: Slippers are small, measured in centimetres.

Exam Tip: Footwear length is in cm.

Question (7). Your own height. ________
Answer: cm (or m)
In simple words: Human height is usually measured in centimetres or metres.

Exam Tip: Both cm and m are acceptable depending on the format.

Question (8). The length of your nail. ________
Answer: cm
In simple words: Fingernails are tiny, measured in centimetres (or millimetres).

Exam Tip: Use cm for very small lengths.

Q.6 Divide the following.

Question (1). Divide \(497\text{ m}\) by 7
Answer: 71 m
Calculation:
\(497 \div 7 = 71\text{ m}\)
In simple words: Divide 497 by 7 using long division to get 71.

Exam Tip: \(7 \times 70 = 490\), and \(7 \times 1 = 7\).

Question (2). Divide \(8\text{ km } 020\text{ m}\) by 4
Answer: 2 km 005 m
Calculation:
\(8\text{ km} \div 4 = 2\text{ km}\)
\(20\text{ m} \div 4 = 5\text{ m}\)
Total = \(2\text{ km } 005\text{ m}\)
In simple words: Divide kilometres and metres separately by 4.

Exam Tip: Ensure placeholder zeros are kept (020 divided by 4 is 005).

Q.7 Solve the following.

Question (1). An old scooter needs to rest every 3 km travelled. How many times will the scooter need to rest in a 39 km journey?
Answer: 12 times (or 13 depending on journey completion)
Calculation:
Total distance = 39 km
Rest interval = 3 km
Number of rests = \(39 \div 3 - 1 = 13 - 1 = 12\) (or 13 if resting at the final destination)
In simple words: Divide total distance by the rest interval.

Exam Tip: Read carefully whether a rest is taken right at the end point.

Question (2). In a race Shyam runs 4 km 370 m and Ram runs 2 km 594 m. Who runs more and by how much?
Answer: Shyam runs more by 1 km 776 m
Calculation:
Shyam's distance = \(4370\text{ m}\)
Ram's distance = \(2594\text{ m}\)
Difference = \(4370 - 2594 = 1776\text{ m} = 1\text{ km } 776\text{ m}\)
In simple words: Subtract Ram's distance from Shyam's distance after converting both to metres.

Exam Tip: Shyam has a larger kilometre value, so he clearly ran more.