2. Reading a Straight Edge Created By: Dr. A. Dávila

9. Look at your straight edge closely to identify which system to use. For the customary system, it might read in for inches or ft for feet. For the metric system, it might read cm for centimeter or mm for millimeter.

10. Most straight edge rulers have an excess edge.

11. If it does have an excess edge, start measuring from the first mark.

12. Each number identifies a whole. 1 centimeter

13. Notice the longer line segment and its corresponding number. whole centimeter

14. Notice the longer line segment and its corresponding number. This identifies the first whole centimeter. whole centimeter

15. Count the number of spaces between each line segment. Each space represents a millimeter. How many millimeters make a whole centimeter? fractions of a centimeter

16. Notice the first small line segment. This small line segment represents the first millimeter (on the meter side of a straight edge). 1 millimeters or 0.1 (1/10) of a cm

17. Notice the first small line segment. This small line segment represents the first millimeter (on the meter side of a straight edge). 2 millimeters or 0.2 (2/10 or 1/5) of a cm

18. Notice the first small line segment. This small line segment represents the first millimeter (on the meter side of a straight edge). 3 millimeters or 0.3 (3/10) of a cm

19. Notice the first small line segment. This small line segment represents the first millimeter (on the meter side of a straight edge). 4 millimeters or 0.4 (4/10 or 2/5) of a cm

20. Notice the first small line segment. This small line segment represents the first millimeter (on the meter side of a straight edge). 5 millimeters or 0.5 (5/10 or 1/2) of a cm

21. It takes 10 millimeters to make a whole centimeter. one centimeter one millimeter

22. How many centimeters make a whole decimeter? one decimeter

23. It takes 10 centimeters to make a whole decimeter. How many decimeters make a meter? one decimeter is equal to 10 cm

24. It takes 10 centimeters to make a whole decimeter. How many decimeters make a meter? 1/10 (0.1) of a decimeter

25. It takes 10 centimeters to make a whole decimeter. How many decimeters make a meter? 2/10 or 1/5 (0.2) of a decimeter

26. It takes 10 centimeters to make a whole decimeter. How many decimeters make a meter? 3/10 (0.3) of a decimeter

27. It takes 10 centimeters to make a whole decimeter. How many decimeters make a meter? 4/10 or 2/5 (0.4) of a decimeter

28. It takes 10 centimeters to make a whole decimeter. How many decimeters make a meter? 5/10 or 1/2 (0.5) of a decimeter

29. Count the number of spaces between each line segment. Each space represents a fraction of an inch. How many sections make a whole inch? fractions of an inch

30. There are a total of 16 sections to a whole inch. fractions of an inch

31. Notice the first small line segment. This small line segment represents the first fractional part of an inch. 1/16 which means 1 out of 16 sections or 0.0625 of an inch

32. 2/16 or 0.125 of an inch Two fractional parts of an inch (2 out of 16 sections).

33. 2/16 or 1/8 means (1 out of 8) or 0.125 of an inch However, the every two sections can be combined for total of eight sections.

34. 3/16 or 0.1875 of an inch Three fractional parts of an inch (3 out of 16 sections).

35. 4/16 or 0.25 of an inch Four fractional parts of an inch (4 out of 16 sections).

36. However, two sections can be grouped for a total of eight sections. 4/16 or 2/8 means (2 out of 8) 0.25 of an inch

37. However, four sections can be grouped for a total of four sections. 4/16 or 1/4 means (1 out of 4) 0.25 of an inch

38. 5/16 or 0.3125 of an inch Five fractional parts of an inch (5 out of 16 sections).

39. 6/16 or 0.375 of an inch Six fractional parts of an inch (6 out of 16 sections).

40. 6/16 or 3/8 0.375 of an inch However, every two sections were paired for a total of 8 sections.

41. 7/16 or 0.4375 of an inch Seven fractional parts of an inch (7 out of 16 sections).

42. 8/16 or 0.5 of an inch Eight fractional parts of an inch (8 out of 16 sections).

43. 8/16 or 4/8 0.5 of an inch However, every two sections can be combined for a total of 8 sections.

44. 8/16 or 2/4 means 2 out of 4 or 0.5 of an inch However, every four sections can be combined for a total of four sections.

45. 8/16 or 1/2 means 1 out of 2 or 0.5 of an inch However, every eight sections can be combined for a total of 2 sections.

46. 9/16 or 0.5625 of an inch Nine fractional parts of an inch (9 out of 16 sections).

47. 10/16 or 0.625 of an inch Ten fractional parts of an inch (10 out of 16 sections).

48. 10/16 or 5/8 0.625 of an inch However, every two sections can be combined for a total of 8 sections.

49. 11/16 or 0.6875 of an inch Eleven fractional parts of an inch (11 out of 16 sections).

50. 12/16 or 0.75 of an inch Twelve fractional parts of an inch (12 out of 16 sections).

51. 12/16 or 6/8 0.75 of an inch However, every two sections can be combined for a total of 8 sections.

52. 12/16 or 3/4 means 3 out of 4 or 0.75 of an inch However, every four sections can be combined for a total of four sections.

53. 13/16 or 0.8125 of an inch Thirteen fractional parts of an inch (13 out of 16 sections).

54. 14/16 or 0.875 of an inch Fourteen fractional parts of an inch (14 out of 16 sections).

55. 14/16 or 7/8 0.875 of an inch However, every two sections can be combined for a total of 8 sections.

56. 15/16 or 0.9375 of an inch Fifteen fractional parts of an inch (15 out of 16 sections).

57. 16/16 or 1 whole inch Sixteen fractional parts of an inch (16 out of 16 sections).

58. 16/16 or 8/8 means 8 out of 8 1 whole inch However, every two sections can be combined for a total of 8 sections.

59. 16/16 or 4/4 means 4 out of 4 or 1 whole inch However, every four sections can be combined for a total of four sections.

60. 16/16 or 2/2 means 2 out of 2 or 1 whole inch However, every eight sections can be combined for a total of 2 sections.

61. 16/16 or 1/1 means 1 out of 1 or 1 whole inch All the sections form one whole inch