Estimation of Numbers || Rounding Off Large Numbers

Rounding off to the nearest 10

  • If the digit in the ones place is 0, 1, 2, 3, or 4 (i.e. < 5) then replace ones place by ‘0’.

  • If the digit in the ones place is 5, 6, 7, 8 or 9 (i.e. > 5 or = 5, but < 10), then replace ones digit by ‘0’ and add 1 to the tens place.

Rounding off to the nearest 100

  • If the digit in tens place is 0, 1, 2, 3, or 4 (i.e. < 5) then replace ones and tens places by ‘0’.

  • If the digit in the tens place is 5, 6, 7, 8 or 9 (i.e. > 5 or = 5, but < 10), then replace ones and tens places by ‘0’ and add 1 to the hundreds place. Rounding off to the nearest 1000

Rounding off to the nearest 1000

  • If the digit in the hundred place is 0, 1, 2, 3, or 4 (i.e. < 5) then replace ones, tens and hundred places by ‘0’. 

  • If the digit in the hundreds place is 5, 6, 7, 8 or 9 (i.e. > 5 or = 5, but < 10), then replace ones, tens and hundred places by ‘0’ and add 1 to the thousands place.

 Examples : -

 Rounding off to the nearest 10,000

  • If the digit in the thousands place is 0, 1, 2, 3, or 4 (i.e. < 5) then replace ones, tens, hundred and thousand places by ‘0’.

  • If the digit in the thousands place is 5, 6, 7, 8 or 9 (i.e. > 5 or = 5, but < 10), then replace ones, tens, hundred and thousands places by ‘0’ and add 1 to the ten thousands place.

Rounding off to the nearest 1,00,000

  • If the digit in the ten thousands place is 0, 1, 2, 3, or 4 (i.e. < 5) then replace ones, tens, hundred, thousand and ten thousand places by ‘0’.

  • If the digit in the ten thousands place is 5, 6, 7, 8 or 9 (i.e. > 5 or = 5, but < 10), then replace ones, tens, hundreds, thousands and ten thousands places by ‘0’ and add 1 to the lakh place.

Practice Exercise :

QA ) Round off to the nearest 10.
  1.  3               ___________
  2.  9765         ___________
  3.  67             ___________
  4.  34,98,675 ___________
  5.  09             ___________
  6.  205           ___________
QB ) Round off to the nearest 100.
  1.   65,768 ___________
  2.  3,671 ___________
  3.  12,786 ___________
  4.  4500 ___________
  5.  1,57,900 ___________
  6.  1,15,143 ___________
QC ) Round off to the nearest 1000.
  1.   44,999 ___________
  2.  10,999 ___________
  3.  7,77,777 ___________
  4.  99,001 ___________
  5.  1,04,670 ___________
  6.   2,12,340 ___________
 QD ) Round off to the nearest 10,000.
  1.   2,78,900 ___________
  2.  5,66,777 ___________
  3.  9,90,789 ___________
  4.  9,12,345 ___________
  5.  4,44,444 ___________
  6.  64,676 ___________
QE ) Round 13,67,899 to the….
  1. Nearest 10
  2. Nearest 100
  3. Nearest 1,000
  4. Nearest 10,000
  5. Nearest 1,00,000
Q F ) Round 4,49,711 to the….
  1. Nearest 10
  2. Nearest 100
  3. Nearest 1,000
  4. Nearest 10,000
  5. Nearest 1,00,000
Q G ) Round 71,34,199 to the….
  1. Nearest 10
  2. Nearest 100
  3. Nearest 1,000
  4. Nearest 10,000
  5. Nearest 1,00,000
Q H) Round 1,11,899 to the….
  1. Nearest 10
  2. Nearest 100
  3. Nearest 1,000
  4. Nearest 10,000
  5. Nearest 1,00,000

QI ) Do as Directed

Q1) Solve the given calculations and estimate your answer to its highest place.

a) 735617 - 584152

b) 3892  X 99

c) 90091 ➗8

d) 8900721 + 339919

e) 678954 ➗ 25

f) 87659 X 104

g) 98765  + 678965 + 789

h) 53762 - 18445

Q2) Do as directed 

a) Number : 34553588

i) Round off the number to nearest tens

ii) Round off the number to nearest hundreds

iii) Round off the number to nearest thousands

iv) Round off the number to nearest ten thousands

v) Round off the number to nearest lakhs

vi) Round off the number to nearest ten lakhs

vii) Round off the number to highest place 

Q3) Solve

a) 3762 ➗9

b) 1549 X 75

c) 69044 ➗ 45

d) 3852 X 257

e) 4267 ➗ 13

f)  17898 ➗ 12

g) 2367 X 234