1. Significant Digits & Rounding

2. RULES FOR DETERMINING SD
1) NON ZERO NUMBERS ARE ALWAYS SIGNIFICANT.
2) A ZERO BETWEEN TWO NUMBERS IS SIGNIFICANT.
3) ZEROS USED TO SPACE THE DECIMAL POINT ARE NOT SIGNIFICANT.
4) ANY ZEROS AFTER THE DECIMAL POINT AND AFTER A NUMBER ARE SIGNIFICANT.

3. EXAMPLES OF RULES
NON ZERO NUMBERS
234 = 3 SD
1987 = 4 SD
12 = 2 SD

4. 2) ZEROS BETWEEN 204 = 3 SD 1907 = 4 SD 101.0101 = 7 SD
EXAMPLES OF RULES
2) ZEROS BETWEEN
204 = 3 SD
1907 = 4 SD
= 7 SD

5. EXAMPLES OF RULES
3) SPACING THE DECIMAL POINT
2340 = 3 SD
= 4 SD
= 2 SD

6. 4) AFTER THE DECIMAL POINT 0.002340 = 4 SD .001907 = 4 SD
EXAMPLES OF RULES
4) AFTER THE DECIMAL POINT
(BOTH CONDITIONS MUST BE TRUE)
= 4 SD
= 4 SD
= 4 SD

7. WORKSHEET
1) 208 =3
2) 1876 =4
3) 2.00 =3
4) 420 =2
5) =5
6) 2000 =1
7) =5
8) =4
9) =3

8. WORKSHEET
10) = 5
11) 1800 =2
12) = 5
13) = 6
14) = 4
15) 1,000,000.0 =8
16) = 6
17) =5
18) = 4

9. WORKSHEET CONTINUED 19) 0.0000001 = 1 20) 259.95 = 5 21) 7.50 = 3
22) = 3
23) 1607 =4
24) = 5
25) = 4

10. ROUNDING OFF TO 3 SD
MAKE SURE YOUR ANSWER HAS 3 SD THEN LOOK AT THE 4TH DIGIT TO DETERMINE IF YOU ROUND UP OR LEAVE IT ALONE

11. The answer should have 3 digits 123
ROUNDING EXAMPLES
The answer should have 3 digits 123
Look at the 5 and then round up to 124

12. ROUNDING EXAMPLES
1,437
USE THE COMMA TO KEEP THE DECIMAL POINT IN THE PROPER PLACE. THE 7 ROUNDS UP THE 3 TO A 4. USE A ZERO TO PLACE THE DECIMAL POINT.
1,440

13. ROUNDING EXAMPLES
THE ZEROS IN FRONT ARE NOT SD BUT THEY ARE USED TO SPACE THE DECIMAL POINT.

14. 1)   
2)    6.941
3)   
4)   
5)   
6)   
7)   
8)   
9)   
10)

15. 11)
12)
13)
14) 1,274
15) 21,643
16) 157,678
17) 1,
18)
19)
20)

16. WORKSHEET ROUNDING 1) 1.01 9) 20.2 2) 6.94 10) 23.0
1) ) 20.2
2) ) 23.0
3) )
4) )
5) ) 209
6) ) 1,270
7) ) 21,600
8) ) 158,000

17. ROUNDING WORKSHEET CONT.
17) 1,460
18) 146
19) 115
20) 133

18. HOMEWORK
Choose 10 from the top determine the number of SD. Choose 10 from the bottom Round off to 3SD

19. SD HOMEWORK
1) 33.40=4 2) 405=3 3) 0.678=3 4) 6.104=4 5) 501.0=4 6) 23500=3 7) =5

20. SD HOMEWORK
8) =3 9) =5 10) =4 11) =5 12) 860=2 13) 937,000=3 14) =5 15) 41030=4

21. SD HOMEWORK
16) =3 17) 569,300=4 18) =4 19) =6 20) =4

22. ROUNDING HOMWEORK 1) 121.842= 122 2) 112.417= 112 3) 35.589= 35.6
4) = 50.9
5) = 0.224
6) = 205

23. ROUNDING HOMWEORK 7) 0.00001839= 0.0000184 8) 0.1148= 0.115
9) = 101
10) = 20.7
11) = 0.239
12) 186,271= 186,000
13) 441,237= 441,000
14) = 207

24. ROUNDING HOMWEORK 15) 63.5846= 63.6 16) 0.006998= 0.00700
17) = 108
18) =
19) =
20) =