Samacheer Kalvi Class 4 Maths Solutions Term 2 Chapter 2 Numbers Exercise 2.1

Tamilnadu Samacheer Kalvi 4th Maths Solutions Term 2 Chapter 2 Numbers Ex 2.1

Question 1. Multiply the following numbers by using lattice method.
(i) 52 × 49
(ii) 347 × 5
(iii) 127 × 7
(iv) 65 × 37
(v) 789 × 4
(vii) 37 × 29
Answer:
(i) 52 × 49 = 2548
(ii) 347 × 5 = 1735
(iii) 127 × 7 = 889
(iv) 65 × 37 = 2405
(v) 789 × 4 = 3156
(vii) 37 × 29 = 1073
In simple words: The lattice method uses a grid to break down multiplication into smaller, easier steps. You multiply digits in cells and then add them diagonally to get the final product.

🎯 Exam Tip: Remember to add the numbers along the diagonals correctly, carrying over tens when needed. Each diagonal sums up to one digit of the final product.

Question 2. Multiply the following numbers by using standard method
(i) 72 × 29
(ii) 31 × 27
(iii) 93 × 42
(iv) 124 × 6
(v) 206 × 8
(vi) 479 × 3
Answer:
(i) 72 × 29
   72
x 29
 648 (72 × 9)
1440 (72 × 20)
2088

(ii) 31 × 27
   31
x 27
 217 (31 × 7)
 620 (31 × 20)
 837

(iii) 93 × 42
   93
x 42
 186 (93 × 2)
3720 (93 × 40)
3906

(iv) 124 × 6
 124
  x 6
 744

(v) 206 × 8
 206
  x 8
1648

(vi) 479 × 3
 479
  x 3
1437
In simple words: The standard multiplication method means you multiply numbers by digits in columns, starting from the right. You multiply by each digit of the bottom number and then add the results.

🎯 Exam Tip: Always remember to carry over any tens to the next column and to place a zero in the ones place when multiplying by the tens digit (or higher place values) of the bottom number.

Question 3. One box contains 25 apples. How many apples are there in 36 such boxes?
Answer:
Number of apples in one box = 25
Number of apples in 36 boxes = 25 × 36
   25
x 36
 150 (25 × 6)
 750 (25 × 30)
 900
So, there are 900 apples in 36 boxes. This is a simple multiplication problem to find the total.
In simple words: To find the total number of apples, you multiply the number of apples in one box by the number of boxes.

🎯 Exam Tip: For "how many total" questions involving equal groups, multiplication is usually the correct operation. Clearly state what each number in your calculation represents.

Question 3. (i) There are 28 pages in a daily newspaper. If Ajay buys newspapers for 45 days, how many pages will it contain?
Answer:
Number of pages in one daily newspaper = 28
Number of days Ajay buys newspapers = 45
Total number of pages in 45 days = 28 × 45
   28
x 45
 140 (28 × 5)
1120 (28 × 40)
1260
So, Ajay will have 1260 pages of newspapers in 45 days. This calculation helps determine the total paper volume.
In simple words: To find the total pages, multiply the number of pages per day by the number of days.

🎯 Exam Tip: When solving word problems, write down the known information and what you need to find. This helps to set up the correct calculation.

Question 3. (ii) A truck carries 125 bags of rice. If each bag has 9 kg of rice, how much kg of rice will there be in the truck?
Answer:
Number of bags of rice = 125
Weight of each bag = 9 kg
Total weight of rice in the truck = 125 × 9 kg
 125
  x 9
1125
So, there will be 1125 kg of rice in the truck. This helps the truck driver know the total load.
In simple words: Multiply the number of bags by the weight of each bag to find the total weight of rice.

🎯 Exam Tip: Pay attention to the units (e.g., kg, pages, apples) in your answer to make sure it makes sense in the context of the problem.

Question 3. (iii) If the cost of one chair is Rs. 857. What will be the cost of 6 chairs?
Answer:
Cost of one chair = Rs. 857
Number of chairs = 6
Cost of 6 chairs = 857 × 6
 857
  x 6
5142
So, the cost of 6 chairs will be Rs. 5142. Knowing the unit price allows for bulk purchase calculations.
In simple words: Multiply the cost of one chair by the number of chairs you want to buy to find the total cost.

🎯 Exam Tip: Always include the currency symbol (Rs. in this case) with your final answer when dealing with money problems.