Solved Questions on Estimation of Numbers
1. A cricket match is watched by 35,547 people. Round this number to the nearest hundred?
a) 36,000
b) 36,500
c) 34,500
d) 35,500
Answer: d) 35,500
Explanation: To write the number 35,547 correctly to the nearest hundred, you need to round it to the nearest multiple of 100. In our case, since the tens digit is 4, we round down.
So, the number 35,547 rounded to the nearest hundred is 35,500.
2. Estimate the value of (43 x 26) / (17 - 8) to the nearest whole number.
a) 100
b) 110
c) 120
d) 130
Answer: c) 120
Explanation: To estimate the value of the expression, we can round the numbers to nearest tens. In this case, we can round 43 to 40 and 26 to 30. We can also round 17 to 20 and 8 to 10.
Therefore, the estimated value of the expression is (40 x 30) / (20 – 10) = 120.
3. Estimate: 3.4 x 2.7 / 0.7?
a) 6
b) 8
c) 7
d) 9
Answer: d) 9
Explanation: To estimate the value of the expression, we can rounded of the numbers. In this case, we can round 3.4 to 3 because 4 is less than 5, 2.7 to 3 because 7 is greater than 5, and 0.7 to 1 because 7 is greater 5.
Therefore, the estimated value of the expression is 3 x 3/1 = 9.
4. Estimate: (72.4 + 39.9) x 8.7?
a) 900
b) 1008
c) 998
d) 1017
Answer: b) 1008
Explanation: To estimate the value of the expression, we can rounded of the numbers. In this case, we can round 72.4 to 72 because 4 is less than 5, 39.9 to 40 because 9 is greater than 5 and 8.7 to 9 because 7 is greater 5.
Therefore, the estimated value of the expression is (72 + 40) x 9 = 1008.
5. Estimate: 32.6% of 860?
a) 270
b) 280
c) 297
d) 300
Answer: c) 297
Explanation: To estimate the value of the expression, we can rounded of the numbers. In this case, 32.6% can be rounded to 33% = 33/100 = 0.33.
Therefore, the estimated value of the expression is 0.33 x 860 = 283.8.
Practice Questions on Estimation of Numbers
1. What is the estimated number of jellybeans in a jar if there are 359 and you estimate it to be around a hundred?
a) 375
b) 390
c) 385
d) 400
Answer: d) 400
2. What is the estimate of the sum of 825 and 732?
a) 1500
b) 1300
c) 1600
d) 1700
Answer: a) 1500
3. Round off 4862 to the nearest thousand.
a) 5000
b) 4000
c) 4800
d) 4900
Answer: a) 5000
4. Estimate the product using general rule: 23 and 44.
a) 1000
b) 900
c) 800
d) 700
Answer: c) 800
5. Estimate the quotient of 872 divided by 9.
a) 90
b) 95
c) 100
d) 105
Answer: c) 100
6. Round off 55614 to the nearest thousand.
a) 45200
b) 56000
c) 55000
d) 56500
Answer: b) 56000
7. Round off 1248 to the nearest hundred.
a) 1200
b) 1300
c) 1400
d) 1500
Answer: a) 1200
8. Estimate the sum of 46 + 63.
a) 100
b) 105
c) 110
d) 115
Answer: c) 110
9. Estimate the product using general rule: 17 and 12.
a) 170
b) 180
c) 190
d) 200
Answer: d) 200
10. Estimate the value of (4321 x 8764) / (1234 x 5678) to the nearest thousand.
a) 5
b) 6
c) 7
d) 8
Answer: b) 6
