Rounding the whole numbers : i. 6.42 = 6, ii. 6.50 = 7
Rounding to Whole Numbers (āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻž)
When rounding a decimal number to the nearest whole number, look at the tenths digit (the first digit after the decimal point.
(āĻĻāĻļāĻŽāĻŋāĻ āĻ¸āĻāĻā§āĻ¯āĻžāĻ āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° (Round) āĻā§°āĻŋāĻŦāĻ˛ā§ āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻāĻā§ (āĻĻāĻļāĻŽāĻŋāĻ āĻŦāĻŋāĻ¨ā§āĻĻā§ā§° āĻĒāĻŋāĻā§° āĻĒā§ā§°āĻĨāĻŽ āĻ āĻāĻ) āĻāĻžāĻŦ āĻ˛āĻžāĻā§āĨ¤
Rule (āĻ¨āĻŋā§āĻŽ): 5 or more, round up; 4 or less, let it rest." (āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻŋāĻŦāĻ˛ā§ āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻ āĻāĻžāĻāĻāĨ¤ 0–4 āĻšāĻ˛ā§ āĻāĻā§āĻ ā§°āĻžāĻāĻ (round down), 5–9 āĻšāĻ˛ā§ āĻāĻĒā§°āĻ˛ā§ āĻ˛āĻāĻ (round up)āĨ¤")
Examples
- 15.3 → 15 (3 is less than 5, so round down)
- 15.6 → 16 (6 is 5 or more, so round up)
- 6.42 → 6 (4 is less than 5)
- 6.78 → 7 (7 is 5 or more)
- 15.5 → 16 (5 rounds up)
Practice
- 8.2 → 8
- 8.5 → 9
- 12.4 → 12
- 12.8 → 13
- 19.5 → 20
- 25.1 → 25
Note: A number like 15.5 is exactly halfway between 15 and 16. By convention, it is rounded up to 16.
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MCQs on Rounding to Whole Numbers (āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻž)
1. Round 7.2 to the nearest whole number. / 7.2-āĻ āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻāĨ¤
A. 6 B. 7 C. 8 D. 9
Ans: B. 7
Explanation: The tenths digit is 2. Since 2 is less than 5, round down to 7. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻ 2, 5-āĻ¤āĻā§ āĻ¸ā§°ā§, āĻ¸ā§ā§ā§ 7-āĻāĻ āĻĨāĻžāĻā§āĨ¤
2. Round 7.8 to the nearest whole number. / 7.8-āĻ āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻāĨ¤
A. 7 B. 8 C. 9 D. 10
Ans: B. 8
Explanation: The tenths digit is 8. Since 8 is 5 or more, round up to 8. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻ 8, 5 āĻŦāĻž āĻ¤āĻžāĻ¤āĻā§ āĻĄāĻžāĻā§°, āĻ¸ā§ā§ā§ āĻāĻĒā§°āĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻŋ 8 āĻĒā§ā§ąāĻž āĻ¯āĻžā§āĨ¤
3. Round 15.4 to the nearest whole number. / 15.4-āĻ āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻāĨ¤
A. 14 B. 15 C. 16 D. 17
Ans: B. 15
Explanation: The tenths digit is 4. Since 4 is less than 5, keep 15. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻ 4āĨ¤ 4, 5-āĻ¤āĻā§ āĻ¸ā§°ā§, āĻ¸ā§ā§ā§ 15-āĻāĻ āĻĨāĻžāĻā§āĨ¤
4. Round 15.5 to the nearest whole number. / 15.5-āĻ āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻāĨ¤
A. 15 B. 16 C. 17 D. 18
Ans: B. 16
Explanation: The tenths digit is 5. By convention, 5 rounds up. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻ 5āĨ¤ āĻ¨āĻŋā§āĻŽ āĻ āĻ¨ā§āĻ¸ā§°āĻŋ 5 āĻš’āĻ˛ā§ āĻāĻĒā§°āĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻž āĻšā§āĨ¤ āĻ¸ā§ā§ā§ 16āĨ¤
5. Round 12.9 to the nearest whole number. / 12.9-āĻ āĻ¨āĻŋāĻāĻāĻ¤āĻŽ āĻĒā§ā§°ā§āĻŖ āĻ¸āĻāĻā§āĻ¯āĻžāĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻāĨ¤
A. 11 B. 12 C. 13 D. 14
Ans: C. 13
Explanation: The tenths digit is 9. Since 9 is greater than 5, round up to 13. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĻāĻļāĻŽāĻžāĻāĻļā§° āĻ āĻāĻ 9āĨ¤ 9, 5-āĻ¤āĻā§ āĻĄāĻžāĻā§°, āĻ¸ā§ā§ā§ 13āĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻšā§āĨ¤
Rule / āĻ¨āĻŋā§āĻŽ: i. 0, 1, 2, 3, 4 → Round Down / āĻ¤āĻ˛āĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻ, ii. 5, 6, 7, 8, 9 → Round Up / āĻāĻĒā§°āĻ˛ā§ āĻā§āĻ˛āĻžāĻāĻžā§° āĻā§°āĻ
- "5 or more, round up; 4 or less, let it rest." ("5 āĻŦāĻž āĻ¤āĻžāĻ¤āĻā§ āĻĄāĻžāĻā§° āĻš’āĻ˛ā§ āĻāĻĒā§°āĻ˛ā§ āĻ¯āĻžāĻāĻ; 4 āĻŦāĻž āĻ¤āĻžāĻ¤āĻā§ āĻ¸ā§°ā§ āĻš’āĻ˛ā§ āĻāĻā§āĻ ā§°āĻžāĻāĻāĨ¤")