Estimating Sum or Difference

Q. In a class, 8 students out of 28 have a dog as their pet animal at home, 6 students have a cat as their pet animal. 10 students have dog and cat both, then how many students do not have a dog or cat as their pet animal at home ?

Q.

The place value of $6$ in the smallest $4$ digit number so formed by using the digits $2,8,6\left(whereoneofthedigitsisallowedtorepeattwiceonly\right)$ is

1. $6$

2. $60$

3. $600$

4. $6000$

Q.

Yuvraj was asked to estimate the sum of 4689 + 19316 and 108 + 2499. Explain with proper steps. [4 MARKS]

Q.

A student while doing a math problem , misplaced the decimal point. Due to this the digit at thousandths place became the digit at hundredths place. Identify the number which the child had written incorrectly if the actual number was 45.6547.

1. 4565.47

2. 456.547

3. 4.56547

4. 45654.7

Q. Solve this :

Q6. Round off 68359 to nearest ten, hundred, thousand and ten thousand

Q. 8. If a+b+c=0 then find the value of

Q. 47. If a sum of 2 numbers is -(4567) in that one of the number is +(74.4884)

Q.

Question 50

In the following question, state whether the given statement is true (T) or false (F).
The estimated sum of 7826 and 12469 rounded off to hundreds is 20, 000.

Q.

The sum of first 20 natural numbers is ___

1. 200

2. 215

3. 210

4. 205

Q. Calculate 63 × 38

1. 2394
2. 2424
3. 2494
4. 2324

Q. Simplify by rationalising the denominator : 16 / 4 - under root 32.

Q. Convert 9999999 dollar into INR

Q. What will we get if one is added to the greatest 3 digit number?

1. One lakh
2. One hundred
3. Ten thousand
4. One thousand

Q. If P equal to whole root 16 +8√3 - whole root 21- 12√3 then what is the value of p? ​

Q. If $a+b+c=15$ and $a^2+b^2+c^2=83$, find the value of $a^3+b^3+c^3-3abc$

1. 180
2. 71
3. 128
4. 95

Q.

A committe of 7 has to be formed from 9 boys and 4 girls. In how many ways can this be done when the committe consists of

1) Atleast 3 girls

2) Atmost 3 girls