CBSE Class 4 Maths Revision Worksheet Set 14

MATH

If you have read the book TIGERS FOR DINNER do Activity 4 and if you have read the book THE HIDDEN POOL do Activity 5.

Activity 4:- LET'S TALK THE CODE WAY

A code is a way of writing a message in secret.
Each letter of the alphabet is replaced by a number.
A-1 B-2 C-3 D-4 E-5 F-6 G-7 I-8.... Z-26
So if you want to write: I AM A STUDENT
You will write your secret message as:
8 1 13 1 19 20 21 4 5 14 20
Write 4 sayings of Mehmood from the book TIGERS FOR DINNER and decode it as shown in the image on A4 size coloured sheet.

Question 1. [Activity 4 Project Task] Transcribe and decode 4 sayings of Mehmood from the book TIGERS FOR DINNER using the given numerical alphabet code.
Answer: Students should select 4 memorable quotes spoken by Mehmood in the book 'TIGERS FOR DINNER', write them out, and convert each letter into its corresponding number according to the rule A-1, B-2, up to Z-26, presenting the final output creatively on an A4 size colored sheet.
In simple words: Replace every letter in Mehmood's quotes with its position number in the alphabet (from 1 to 26).

Exam Tip: Ensure spaces between words are clearly maintained in numerical secret codes so that numbers do not merge together.

Activity 5:- CREATE A BOARD GAME

You have read the story of beetle race from the book 'THE HIDDEN POOL' by Ruskin Bond. Follow the instructions to create a board game.
1. Create a race track for the beetle race as described in the story on a half chart paper and paste it on a card board.
2. Make the game board, dice, colourful beetles using cardboard.
3. While designing the board game give proper space in between the tracks. Also, highlight starting and finishing point.
4. Write the rules for the game on a separate sheet/card and stick it at the back of the Board game.

Question 2. [Activity 5 Project Task] Follow the given instructions to design, construct, and write the rules for the beetle race board game based on Ruskin Bond's 'THE HIDDEN POOL'.
Answer: This is a hands-on creative activity where students build a physical board game incorporating a winding track, start and finish markers, handmade cardboard beetles, custom dice, and a written set of rules pasted on the reverse side.
In simple words: Build a fun board game based on the beetle race story with clear tracks, tokens, and rules.

Exam Tip: Make sure the track paths are wide enough so that the cardboard beetles fit comfortably inside each space.

LET'S PRACTICE MATH

Do the following questions according to the instructions. Solve Worksheet 1 and 2.

Q1. NUMBER RIDDLE: WHO AM I?
From old calendars, cut out digits 0 to 9 and stick them in a creative manner. Make sure the digits are not too small. Use the digits to answer each number riddle. To be done on A4 size sheet.
The challenge is to use a digit only once in a number.

a) I am the largest 4-digit odd number you can make.
Answer: 9875
To form the largest 4-digit number using unique digits, arrange the highest available digits in descending order. Since the number must be odd, the units place must be an odd digit (5, 7, or 9). Testing descending combinations gives 9875.
In simple words: Pick the four largest digits and make sure the last digit is odd.

Exam Tip: Always check the units digit first when looking for odd or even number conditions.

b) I am the smallest 5-digit even number you can make.
Answer: 10234
To form the smallest 5-digit number using unique digits, place the smallest non-zero digit in the ten-thousands place (1), followed by 0, 2, 3, and 4 in increasing order. Since 4 is even, the number is 10234.
In simple words: Start with the smallest possible non-zero digits and end with an even digit.

Exam Tip: Remember that a 5-digit number cannot start with 0.

c) I am the largest 5-digit even number you can make that has a 3 in the thousands place.
Answer: 93872
Fix 3 in the thousands place: _ 3 _ _ _. For the ten-thousands place, use the largest remaining digit, 9. For the remaining places (hundreds, tens, units), use the largest available digits (8, 7, 2) in descending order to keep the number as large as possible while ending in an even digit (2).
In simple words: Fix 3 in the thousands place, put 9 first, and use the biggest remaining digits with an even ending.

Exam Tip: Work from left to right, locking in required digit positions first before optimizing the rest.

d) I am the greatest possible number that is greater than 65,450 but less than 65,500.
Answer: 65499
The number must lie between 65,450 and 65,500. To make it as great as possible, maximize the tens and units digits to 9, giving 65,499.
In simple words: Find the highest number just below 65,500.

Exam Tip: Pay close attention to strict inequality bounds (greater than and less than).

e) I am the successor of 72,090.
Answer: 72091
The successor of a number is found by adding 1 to it.
\(72090 + 1 = 72091\)
In simple words: The successor is simply the very next number obtained by adding 1.

Exam Tip: Successor means +1, whereas predecessor means -1.

f) I am the predecessor of 87,654.
Answer: 87653
The predecessor of a number is found by subtracting 1 from it.
\(87654 - 1 = 87653\)
In simple words: The predecessor is the number that comes immediately before by subtracting 1.

Exam Tip: Double-borrowing may be needed when finding predecessors of numbers ending in zeros.

Q2. ROUNDING OFF

a) We are the smallest and largest whole numbers that round to 70 when rounded to the nearest ten. What numbers are we?
Answer: 65 and 74
When rounding to the nearest ten, numbers from 65 to 74 all round to 70. The smallest such whole number is 65 and the largest is 74.
In simple words: The range of numbers rounding to 70 spans from 65 up to 74.

Exam Tip: For rounding to the nearest 10, numbers ending in 5 round up, and numbers ending in 4 round down.

b) The sum of my digits is 11. When rounded to the nearest hundred, I am 500. Rounding to the nearest ten makes me 530.
Answer: 532
Let the number be in the 500s since rounding to the nearest hundred gives 500. Rounding to the nearest ten gives 530, so the number is between 525 and 534. Testing digits for sum 11: \(5 + 3 + 2 = 10\) (not 11), wait: \(5 + 3 + 3 = 11\) gives 533 (rounds to 530, but sum is 11). Let us check digits of 532: \(5 + 3 + 2 = 10\). Let us check digits of 533: \(5 + 3 + 3 = 11\), but rounding 533 to nearest ten is 530. Let us check 524: sum \(5+2+4=11\), rounds to 520. Let us check 532: \(5+3+2=10\). Let us check 526: \(5+2+6=13\). Let us check 524: \(5+2+4=11\), nearest ten is 520. Let us check 533: \(5+3+3=11\), nearest ten is 530, nearest hundred is 500. Therefore, the number is 533.
In simple words: Find a 3-digit number starting with 5 that adds up to 11 and rounds to 530.

Exam Tip: Verify all three conditions (digit sum, nearest hundred, nearest ten) against your final number.

Q3. Write the missing numbers in each pyramid. The sum of two numbers side by side must be equal the number above them.
[Pyramid Structure: Top = 95; Middle = ? and 65; Bottom = ? , 25 , ?]
Answer:
Middle-left box = \(95 - 65 = 30\)
Bottom-left box = \(30 - 25 = 5\)
Bottom-right box = \(65 - 25 = 40\)
In simple words: Subtract the known adjacent number from the box above to find each missing lower block.

Exam Tip: In number pyramids, any block equals the sum of the two blocks directly below it.

Q4. Complete pairs of values in the table for the circle and square to make the balance picture tree. (one of the pair of value is shown). Hint: 3 circles = 2 squares

Answer: Using the ratio \(3 \text{ circles} = 2 \text{ squares}\), each square value is \(\frac{3}{2}\) of the circle value, or each circle value is \(\frac{2}{3}\) of the square value. Completing the table rows gives:
a) 6 circles, 9 squares
b) 3 circles, 2 squares
c) 9 circles, 13.5 squares
d) 12 circles, 18 squares
e) 15 circles, 22.5 squares
f) 18 circles, 27 squares
g) 21 circles, 31.5 squares
In simple words: Maintain the constant ratio where 3 circles weigh the same as 2 squares.

Exam Tip: Set up a proportion equation like \(\frac{\text{Circles}}{3} = \frac{\text{Squares}}{2}\) to easily calculate missing values.

Q5. Here is a table of people who visited Jim Corbett National Park.

Answer the following questions from the information given in the above table in your Math notebook:

a) How many people in all visited Jim Corbett National Park in the month of May and August?
Answer:
Visitors in May = 65395
Visitors in August = 23982
Total visitors = \(65395 + 23982 = 89377\)
In simple words: Add the visitor counts for May and August together.

Exam Tip: Line up place values carefully when adding large numbers.

b) How many more people visited the park in June than in August?
Answer:
Visitors in June = 78324
Visitors in August = 23982
Difference = \(78324 - 23982 = 54342\)
In simple words: Subtract August visitors from June visitors.

Exam Tip: The phrase "how many more" always indicates subtraction.

c) Subtract the sum of people who visited the park in May and August from the sum of people who visited the park in June and July.
Answer:
Sum of May and August = \(65395 + 23982 = 89377\)
Sum of June and July = \(78324 + 35467 = 113791\)
Difference = \(113791 - 89377 = 24414\)
In simple words: Add May+August, add June+July, then find the difference between the two sums.

Exam Tip: Perform calculations in two separate addition steps before doing the final subtraction.

d) Find out the total number of people who visited the park in all four months.
Answer:
Visitors in May = 65395
Visitors in June = 78324
Visitors in July = 35467
Visitors in August = 23982
Total visitors = \(65395 + 78324 + 35467 + 23982 = 203168\)
In simple words: Add the visitor numbers for all four months together.

Exam Tip: Double-check column additions by adding numbers in reverse order.