Samacheer Kalvi Class 4 Maths Solutions Term 1 Chapter 2 Numbers Exercise 2.7

Tamilnadu Samacheer Kalvi 4th Maths Solutions Term 1 Chapter 2 Numbers Ex 2.7

Question 1. Add the following numbers.
(a) 216, 3422, 4019, 497
(b) 1002, 2347, 1976, 2005, 2007
(c) 1978, 1965, 2704, 473
Answer:
(a) \( 216 + 3422 + 4019 + 497 = 8154 \)

🎯 Exam Tip: Always double-check your addition by adding the columns again, or by grouping numbers differently, to catch any calculation errors.

Question 2. Add the total amount of the following 4 piggy banks.
Rs 978
Rs 3796
Rs 2374
Rs 1957
Answer: The total amount from the 4 piggy banks is calculated as:
\( \text{Rs } 978 + \text{Rs } 3796 + \text{Rs } 2374 + \text{Rs } 1957 = \text{Rs } 9105 \)
So, the sum of all the money is Rs 9105. It's a fun way to save and then count money.
In simple words: We add the money from each piggy bank together to find the grand total.

🎯 Exam Tip: When adding money, remember to include the currency symbol (like Rs) in your final answer to show what the number represents.

Question 3. The sum of \( 1215 + 2367 + 1673 + 3120 = \)
(a) 8585
(b) 8225
(c) 8375
(d) 8285
Answer: (c) 8375
To find the sum, we add the given numbers:
\( 1215 + 2367 + 1673 + 3120 = 8375 \)
Adding carefully column by column gives us the correct total.
In simple words: We just add all the numbers together. The correct answer is 8375.

🎯 Exam Tip: For multiple-choice questions, quickly estimate the sum before calculating precisely to eliminate some options, then perform the full calculation.

Question 4. \( 2076 + 276 + 2974 + 1751 = \)
(a) 9561
(b) 7077
(c) 7377
(d) None of the options
Answer: (b) 7077
We add the numbers given in the question:
\( 2076 + 276 + 2974 + 1751 = 7077 \)
This sum can be found by carefully adding each column, starting from the ones place.

🎯 Exam Tip: Be careful to align the numbers correctly by their place values (ones, tens, hundreds, thousands) before starting to add, especially when numbers have different lengths.

Question 5. What is the sum of five hundreds and fifteen tens?
(a) 650
(b) 550
(c) 5150
(d) 6150
Answer: (a) 650
First, we need to convert the words into numbers:
Five hundreds means \( 5 \times 100 = 500 \).
Fifteen tens means \( 15 \times 10 = 150 \).
Now, we add these two numbers together to find the sum:
\( \text{Sum} = 500 + 150 = 650 \). Understanding place values helps convert words to numbers easily.
In simple words: Five hundreds is 500, and fifteen tens is 150. Adding them together gives us 650.

🎯 Exam Tip: Always convert number words (like 'five hundreds' or 'fifteen tens') into their numerical form first before performing any calculations.

Question 6. The sum of the greatest 3 digit number and the smallest 4 digit number is
(a) 1999
(b) 1099
(c) 1990
(d) 9999
Answer: (a) 1999
The greatest 3-digit number is 999.
The smallest 4-digit number is 1000.
To find their sum, we add these two numbers:
\( \text{Sum} = 999 + 1000 = 1999 \). Knowing these special numbers is useful for quick calculations.

🎯 Exam Tip: Remember that the greatest n-digit number is a sequence of n nines, and the smallest n-digit number is 1 followed by n-1 zeros.

Question 7. \( 9999 + 1 = \)
(a) 10,000
(b) 1000
(c) 1001
(d) 10001
Answer: (a) 10,000
When we add 1 to 9999, it rolls over to the next place value, making it 10,000. This is how counting moves from a number ending in all nines to the next higher place value.

🎯 Exam Tip: Adding 1 to a number composed of all 9s always results in a number with one more digit, starting with 1 and followed by zeros.

Question 8. In a village the number of males is 4154 and the number of females is 4221. Find the total population in the village?
Answer:
Number of males = \( 4154 \)
Number of females = \( 4221 \)
To find the total population, we add the number of males and females:
Total population \( = 4154 + 4221 = 8375 \). The total number of people in the village is 8375.

🎯 Exam Tip: For word problems asking for a total, always identify the quantities to be combined and use addition. Make sure to include units in the answer.

Question 9. A refrigerator costs Rs 6543 and a DVD player costs Rs 3412. What is the total cost?
Answer:
Cost of refrigerator = Rs \( 6543 \)
Cost of DVD player = Rs \( 3412 \)
To find the total cost, we add the cost of the refrigerator and the DVD player:
Total cost \( = \text{Rs } 6543 + \text{Rs } 3412 = \text{Rs } 9955 \). The total money spent is Rs 9955.

🎯 Exam Tip: Always make sure to include the currency symbol (e.g., Rs) when dealing with money problems, both in the steps and the final answer.