CBSE Class 3 Mathematics Addition and Subtraction Set 03

Question I. Form the greatest and the smallest 4-digit number using the digits 7, 0, 5 and 2 with 2 at the hundreds place. Find then sum and difference.
Answer: Given digits: 7, 0, 5, 2.
Condition: Digit 2 must be at the hundreds place.
To form the greatest 4-digit number:
Thousands place = 7
Hundreds place = 2 (fixed)
Tens place = 5
Ones place = 0
Greatest number = 7250

To form the smallest 4-digit number:
Thousands place = 5 (since 0 cannot be at the leading thousands place)
Hundreds place = 2 (fixed)
Tens place = 0
Ones place = 7
Smallest number = 5207

Sum of the numbers = \(7250 + 5207 = 12457\)
Difference of the numbers = \(7250 - 5207 = 2043\)
In simple words: Fix 2 in the middle, arrange the remaining digits from largest to smallest for the greatest number, and smallest to largest (avoiding starting with 0) for the smallest number, then add and subtract them.

Exam Tip: Always remember that the smallest 4-digit number cannot start with 0, so place the next smallest non-zero digit at the thousands place.

Question II. Form the number 500 by either adding or subtracting in ten different ways. For example: a) 410 + 90 = 500 b) 608 - 108 = 500
Answer: 1) 250 + 250 = 500
2) 300 + 200 = 500
3) 450 + 50 = 500
4) 350 + 150 = 500
5) 499 + 1 = 500
6) 600 - 100 = 500
7) 700 - 200 = 500
8) 1000 - 500 = 500
9) 850 - 350 = 500
10) 550 - 50 = 500
In simple words: Write any ten pairs of numbers that either add up to 500 or subtract to give 500.

Exam Tip: You can create many combinations by taking a round number and adjusting it with its complement to 500.

Question III. Complete the table:
Answer: To complete the table, add each row number to the column header value.

In simple words: Add the number on the left edge with the number at the top of each column to fill in every grid cell.

Exam Tip: Double check your addition column by column to avoid silly arithmetic mistakes.

Question IV. Complete the following:
Answer:
a) 6049 is the predecessor of 6050.
b) 600 should be subtracted from 8100 to get 7500. (Calculation: \(8100 - 7500 = 600\))
c) \(475 + 1225 + 1 = 1701\)
d) \(9909 - 909 = 9000\) (Calculation: \(9909 - 9000 = 909\))
e) 2000 less than 8000 is 6000. (Calculation: \(6000 + 2000 = 8000\))
f) \(7866 - 0 = 7866\)
g) \(8799 + 1 = 8800\)
h) \(4327 + 3 = 4330\) (Calculation: \(4330 - 4327 = 3\))
i) \(8111 - 110 = 8001\) (Calculation: \(8111 - 8001 = 110\))
j) The successor of the sum of 2708 and 1983 is 4692. (Calculation: Sum = \(2708 + 1983 = 4691\), Successor = \(4691 + 1 = 4692\))
In simple words: Fill in the missing numbers by performing simple addition, subtraction, or finding predecessors and successors.

Exam Tip: For missing number problems involving subtraction, subtract the result from the starting number or find the difference between the two given numbers.

Question V. Add or subtract the following after writing the missing digits:
Answer:
a) Given vertical arrangement:
\(402\_\)
+ \(29\_9\)
---------
= \(\_24\)
Completing the digits: Let the missing digits be 5 and 6 respectively to make standard valid columns, or solve based on standard school problem templates.
Corrected full problem: \(4025 + 2999 = 7024\)

b) Given vertical arrangement:
\(8467\)
- \(\_5\_9\)
---------
= \(\_17\_\)
Corrected full problem: \(8467 - 2549 = 5918\)
In simple words: Fill in the missing numbers so that the addition or subtraction problem works out correctly.

Exam Tip: Check column borrowing and carrying carefully when working with missing digit vertical operations.

Question VI. 2705 people went to see the circus on the first day. 829 more people visited on the second day, so 3534 people visited on the second day. It rained on the third day, so 1094 less people came as compared to the second day. So the tickets sold on the third day were 2440. The total sold in all the three days were 8679. Maximum number of people on 3534 day and the minimum no of people visited the circus on 2440 day.
Answer:
People on 1st day = 2705
People on 2nd day = \(2705 + 829 = 3534\)
People on 3rd day = \(3534 - 1094 = 2440\)
Total people in all three days = \(2705 + 3534 + 2440 = 8679\)
Maximum number of people visited on the second day (3534).
Minimum number of people visited on the third day (2440).
In simple words: Find the attendance for each day step-by-step using addition and subtraction, then add them all together for the total.

Answer:
First, let us complete the table by calculating the Final Cost for each item (Cost \(\times\) Quantity):

a) Find the total cost of all the items bought by Mohit.
Answer:
Total Cost = Rs. 930 + Rs. 80 + Rs. 124 + Rs. 64 = Rs. 1198
In simple words: Add the final cost of all items together to get the total amount spent.

Exam Tip: Always multiply the unit cost by the quantity before summing up the total bill.

b) Find the difference in the cost of the bag and the paint-box.
Answer:
Cost of bag = Rs. 930
Cost of paint-box = Rs. 124
Difference = Rs. 930 - Rs. 124 = Rs. 806
In simple words: Subtract the cost of the paint-box from the cost of the bag.

Exam Tip: The word 'difference' always implies subtraction between the two given values.

c) How much did the pens and the note-books cost?
Answer:
Cost of pens = Rs. 80
Cost of note-books = Rs. 64
Total combined cost = Rs. 80 + Rs. 64 = Rs. 144
In simple words: Add the total price of pens and note-books together.

Exam Tip: Make sure you use the final calculated cost (after multiplying by quantity) for pens and note-books.