Summary Rounding Off & Significant Numbers Notes

Rounding decimals Roles of Significant Figures 635 >
numbers sig
off whole
-

~
a
.




00635- non .


sig
.
*
Tip :




:
All non-zero
digits are
significant
·


If it is
4 or less
give if a
rest
.
2 All zeros
found605
between non-zero
digits are
significant
5 or more ,
add I more ① .
& 605 .
005


③ Trailing zeros
for a number that ends with a decimal
point
are
significant 00500
whole numbers

Exercise :
Round it off to the digit underlined in red

57 00
4.

Trailing to the right of the decimal point
zeros is



significant ①
.




~ 605
. 000 Imm = 0 . 1 cm

1
6305 : 6300 2 .
57 .




0001 :
57 . 0000

of the first non-zero
1 0 cm
. > 2 s - . f




~
5
All zeros
to the left digit
3 14571
. : 19600 4
. 53 . 9999% =
54 .
0000 are
non-significant ① 00635 3 s f :
.




② 0 . 0010 = 2 s -
.f




5 . 17978 :
17980/ .
6 2999 9781 .
= 3000 .
0 .
6 For values written the scientific
in
notation (Ax 10")
the above rules
only apply to A
.
7
57 . 00100 =
57 0010/.
8 1 . 000576 = 1 .
000581 6000 000 > 6 x 106
-
=




.
9 0 .
100781 = 0 .
1008 .
10 57 051 .
: 57 1r .

Practice How many significant :

figures are
found on




the numbers
given ?

1. 1 .
00301 = 6/ .
2
000010
. =
2-

~
.
3 0 70500
.
=
5 4 . 0057 . 1 =
3 /

~
5 . 5 . 100 =
4/ .
6 10 .
705 :
5

~
~
7 . 501 . 10 =
5 8 . 100 75 .
: 5

~
6
& 00 0756 . =
43 10 .
69 1110
.
: