Rounding
Whole Numbers
Rounding off in Tens
 Rounding off in Tens is to replace a
number with a number that tells how
close it is to the nearest ten.
 Example:
20 21 22 23 24 25 26 27 28 29 30
 27 is closer to 30, so we would round it to
30!
We are rounding to the Tens place,
so we are going to circle the number
in the Tens place.
2 3 7 5
Move to the right,
Underline next number
2, 3 7 5
If underlined number is 0 to 4,
Circle stays the same
2 , 3 7 5
If it is 5 to 9,
Add 1 in circled number. 7+1 = 8
Digits to the right change to ZERO
2 , 3 8 0
We are rounding to the Hundred place,
so we are going to circle the number in
the Hundred place.
2 3 7 5
Move to the right,
Underline next number
2 , 3 7 5
If underlined number is 0 to 4,
Circle stays the same
2 , 3 7 5
If it is 5 to 9,
Add 1 in circled number. 3+1 = 4
Digits to the right change to ZERO
2 , 4 0 0
Rounding to the Thousands place,
so we are going to circle the number in
the Thousand place.
2 3 7 5
Move to the right,
Underline next number
2 , 3 7 5
If underlined number is 0 to 4,
Circle stays the same
2 , 3 7 5
Digits to the right change to ZERO
2 , 4 0 0
When do we round up
and when do we round
down?
Round off the fol owing numbers to the
indicated place value.
Nearest Thousands
1) 78 125
2) 51 789
3) 25 507
4) 6 895
5) 27 023
Round off the fol owing numbers to the
indicated place value.
Nearest Hundred Thousands
1) 8 562 902
2) 5 124 900
3) 12 578 124
4) 9 876 540
5) 567 810
Round off the following numbers to the
indicated place value.
Nearest Millions
1) 14 568 140
2) 29 128 035
3) 50 671 904
4) 47 132 090
5) 1 452 907
 To round off a whole number to a specified
place value, determine the digit to the right
of the place you are rounding off to.
 If the digit is 5,6,7,8, and 9, round it up or
simply add 1 to the digit in the specified
place and replace the digits to the right with
zeros.
 If the digit is less than 5 (4,3,2,1, and
0)retain the digits in the specified place and
replace/change the digits to the right with
zeros
“How do we round numbers?
Question Time
Round to the nearest 10
1. 534
2. 6721
Round to the nearest 100
1. 534
2. 6721
Round to the nearest 1000
1. 534
2. 6721
Assignment:
On page 27 of your book, answer 1 – 15
For numbers 1-3, use the number line
below to round off each number.
Round off each amount to the nearest
hundred thousand pesos
Round off each number to the nearest
millions
Round off each number to the nearest ten
billions.

Math 4-5 roundingoff.pptx

  • 1.
  • 2.
    Rounding off inTens  Rounding off in Tens is to replace a number with a number that tells how close it is to the nearest ten.  Example: 20 21 22 23 24 25 26 27 28 29 30  27 is closer to 30, so we would round it to 30!
  • 3.
    We are roundingto the Tens place, so we are going to circle the number in the Tens place. 2 3 7 5 Move to the right, Underline next number 2, 3 7 5
  • 4.
    If underlined numberis 0 to 4, Circle stays the same 2 , 3 7 5 If it is 5 to 9, Add 1 in circled number. 7+1 = 8 Digits to the right change to ZERO 2 , 3 8 0
  • 5.
    We are roundingto the Hundred place, so we are going to circle the number in the Hundred place. 2 3 7 5 Move to the right, Underline next number 2 , 3 7 5
  • 6.
    If underlined numberis 0 to 4, Circle stays the same 2 , 3 7 5 If it is 5 to 9, Add 1 in circled number. 3+1 = 4 Digits to the right change to ZERO 2 , 4 0 0
  • 7.
    Rounding to theThousands place, so we are going to circle the number in the Thousand place. 2 3 7 5 Move to the right, Underline next number 2 , 3 7 5
  • 8.
    If underlined numberis 0 to 4, Circle stays the same 2 , 3 7 5 Digits to the right change to ZERO 2 , 4 0 0
  • 9.
    When do weround up and when do we round down?
  • 10.
    Round off thefol owing numbers to the indicated place value. Nearest Thousands 1) 78 125 2) 51 789 3) 25 507 4) 6 895 5) 27 023
  • 11.
    Round off thefol owing numbers to the indicated place value. Nearest Hundred Thousands 1) 8 562 902 2) 5 124 900 3) 12 578 124 4) 9 876 540 5) 567 810
  • 12.
    Round off thefollowing numbers to the indicated place value. Nearest Millions 1) 14 568 140 2) 29 128 035 3) 50 671 904 4) 47 132 090 5) 1 452 907
  • 14.
     To roundoff a whole number to a specified place value, determine the digit to the right of the place you are rounding off to.  If the digit is 5,6,7,8, and 9, round it up or simply add 1 to the digit in the specified place and replace the digits to the right with zeros.  If the digit is less than 5 (4,3,2,1, and 0)retain the digits in the specified place and replace/change the digits to the right with zeros “How do we round numbers?
  • 15.
    Question Time Round tothe nearest 10 1. 534 2. 6721 Round to the nearest 100 1. 534 2. 6721 Round to the nearest 1000 1. 534 2. 6721
  • 16.
    Assignment: On page 27of your book, answer 1 – 15 For numbers 1-3, use the number line below to round off each number. Round off each amount to the nearest hundred thousand pesos Round off each number to the nearest millions Round off each number to the nearest ten billions.