1. Grade 3 Mental Math Measurement Estimation – Length

2. Measurement Estimation – Length Strategies There are 2 measurement estimation – length strategies –Benchmark Centimetre –Benchmark Metre

3. Benchmark Centimetre Strategy (Introduction) Students should use personal referents, such as the width of their little fingers for a 1-centimetre benchmark and the width of their hands for a 10-centimetre benchmark. Since a ruler is a very common tool in the classroom, it can serve as a benchmark for 30 centimetres. Using these benchmarks, students should estimate lengths of objects from 1 cm to 50 cm.

4. Benchmark Centimetre Example (Introduction) Assemble a number of objects and prepare a list of ranges for estimates of the lengths you will ask. –Will the height of a wastebasket be about 35 – 45 cm or 20 – 30 cm? Assemble a number of objects that will all have lengths within a reasonable range of values, so you can ask students if the lengths are less than, more than, or about a given measure. –For example, ask students to decide calculator is less than, more than, or about 10 cm as you display it. Have students estimate the length of objects by giving possible answers –For example, ask if an eraser is about 3 cm, 7 cm or 10 cm

5. Benchmark Centimetre Reinforcement (Day 1) Question # 1: Is a piece of lined paper 20 – 30 cm wide or 40 – 50 cm wide?

6. Benchmark Centimetre Reinforcement (Day 1 cont.) Answer:

7. Benchmark Centimetre Reinforcement (Day 1 cont.) Question # 2: Is the waste basket 35 - 45 cm high or 15 to 25 cm high?

8. Benchmark Centimetre Reinforcement (Day 1 cont.) Answer:

9. Benchmark Centimetre Reinforcement (Day 1 cont.) Question # 3: Is a text book 5 – 10 cm think or 15 - 20 cm think?

10. Benchmark Centimetre Reinforcement (Day 1 cont.) Answer:

11. END OF LESSON

12. Benchmark Centimetre Reinforcement (Day 2) Question # 1: Is a new pencil more, less or about 10 cm long?

13. Benchmark Centimetre Reinforcement (Day 2 cont.) Answer:

14. Benchmark Centimetre Reinforcement (Day 2 cont.) Question # 2: Is the top of your desk more, less, or about 30 cm wide?

15. Benchmark Centimetre Reinforcement (Day 2 cont.) Answer:

16. Benchmark Centimetre Reinforcement (Day 2 cont.) Question # 3: Is your hand more, less or about 10 cm wide

17. Benchmark Centimetre Reinforcement (Day 2 cont.) Answer:

18. Benchmark Centimetre Reinforcement (Day 2 cont.) Question # 4: Is a text book more, less or about 40 cm wide?

19. Benchmark Centimetre Reinforcement (Day 2 cont.) Answer:

20. Benchmark Centimetre Reinforcement (Day 2 cont.) Question # 5: Is your arm more, less, or about 30 cm long?

21. Benchmark Centimetre Reinforcement (Day 2 cont.) Answer:

22. END OF LESSON

23. Benchmark Centimetre Reinforcement (Day 3) Question # 1: Is CD about 15 cm, 20 cm or 25 cm wide?

24. Benchmark Centimetre Reinforcement (Day 3 cont.) Answer:

25. Benchmark Centimetre Reinforcement (Day 3 cont.) Question # 2: Is a piece of lined paper about 25 cm, 35 cm or 45 cm wide?

26. Benchmark Centimetre Reinforcement (Day 3 cont.) Answer:

27. Benchmark Centimetre Reinforcement (Day 3 cont.) Question # 3: Is an apple about 10 cm, 20 cm or 30 cm wide?

28. Benchmark Centimetre Reinforcement (Day 3 cont.) Answer:

29. Benchmark Centimetre Reinforcement (Day 3 cont.) Question # 4: Is a new pencil about 10 cm, 20 cm or 30 cm long?

30. Benchmark Centimetre Reinforcement (Day 3 cont.) Answer:

31. Benchmark Centimetre Reinforcement (Day 3 cont.) Question # 5: Is an iPad about 25 cm, 35 cm or 50 cm wide?

32. Benchmark Centimetre Reinforcement (Day 3 cont.) Answer:

33. END OF LESSON

34. Benchmark Centimetre Reinforcement (Day 4) Question # 1: About how wide is a your math text book?

35. Benchmark Centimetre Reinforcement (Day 4 cont.) Answer:

36. Benchmark Centimetre Reinforcement (Day 4 cont.) Question # 2: About how long is a pencil?

37. Benchmark Centimetre Reinforcement (Day 4 cont.) Answer:

38. Benchmark Centimetre Reinforcement (Day 4 cont.) Question # 3: About how tall is a waste basket?

39. Benchmark Centimetre Reinforcement (Day 4 cont.) Answer:

40. Benchmark Centimetre Reinforcement (Day 4 cont.) Question # 4: About how thick is a text book?

41. Benchmark Centimetre Reinforcement (Day 4 cont.) Answer:

42. Benchmark Centimetre Reinforcement (Day 4 cont.) Question # 5: About how wide is your finger?

43. Benchmark Centimetre Reinforcement (Day 4 cont.) Answer:

44. END OF LESSON

45. Benchmark Centimetre Assessment (Day 5) Question # 1: Is a new pencil about 10 cm, 20 cm or 30 cm long?

46. Benchmark Centimetre Assessment (Day 5 cont.) Answer:

47. Benchmark Centimetre Assessment (Day 5 cont.) Question # 2: About how wide is a piece of paper?

48. Benchmark Centimetre Assessment (Day 5 cont.) Answer:

49. Benchmark Centimetre Assessment (Day 5 cont.) Question # 3: About how long is your shoe?

50. Benchmark Centimetre Assessment (Day 5 cont.) Answer:

51. Benchmark Centimetre Assessment (Day 5 cont.) Question # 4: Is your hand more, less or about 10 cm wide

52. Benchmark Centimetre Assessment (Day 5 cont.) Answer:

53. Benchmark Centimetre Assessment (Day 5 cont.) Question # 5: About how wide is an apple?

54. Benchmark Centimetre Assessment (Day 5 cont.) Answer:

55. END OF LESSON

56. Benchmark Metre Strategy (Introduction) Since most door handles are about 1 metre above the floor, students could use this distance as a benchmark for 1 metre. They could use their arm span when their arms are opened wide. Students should be able to measure lengths from 1 to 20 metres

57. Benchmark Metre Example (Introduction) Use more, less or about questions –For example, is the window more, less or about 2 m wide Use a pre-determined list –For example, is the room 3 m, 7 m, or 10 m wide? Use distances of objects –For example, asked students how far away something lies, 1-2 m, 3-4 m, or 5-6 m

58. Benchmark Metre Reinforcement (Day 1) Question # 1: Is your desk more, less, or about 2 m?

59. Benchmark Metre Reinforcement (Day 1 cont.) Answer:

60. Benchmark Metre Reinforcement (Day 1 cont.) Question # 2: Is the classroom ceiling more, less, or about 10 m high?

61. Benchmark Metre Reinforcement (Day 1 cont.) Answer:

62. Benchmark Metre Reinforcement (Day 1 cont.) Question # 3: Is the classroom door more, less, or about 1 m wide?

63. Benchmark Metre Reinforcement (Day 1 cont.) Answer:

64. END OF LESSON

65. Benchmark Metre Reinforcement (Day 2) Question # 1: Are you more, less or about 3 m tall?

66. Benchmark Metre Reinforcement (Day 2 cont.) Answer:

67. Benchmark Metre Reinforcement (Day 2 cont.) Question # 2: Is the classroom door about 1 m, 2 m or 3 m tall?

68. Benchmark Metre Reinforcement (Day 2 cont.) Answer:

69. Benchmark Metre Reinforcement (Day 2 cont.) Question # 3: Is your desk about 1 m, 2 m, or 3 m wide?

70. Benchmark Metre Reinforcement (Day 2 cont.) Answer:

71. Benchmark Metre Reinforcement (Day 2 cont.) Question # 4: Is your classroom 5 m, 10 m, or 20 m wide?

72. Benchmark Metre Reinforcement (Day 2 cont.) Answer:

73. Benchmark Metre Reinforcement (Day 2 cont.) Question # 5: Most cars are about 5 m, 10 m, or 15 m in length?

74. Benchmark Metre Reinforcement (Day 2 cont.) Answer:

75. END OF LESSON

76. Benchmark Metre Reinforcement (Day 3) Question # 1: About how far away is the next desk from you, 1-2 m, 3-4 m or 5-6 m?

77. Benchmark Metre Reinforcement (Day 3 cont.) Answer:

78. Benchmark Metre Reinforcement (Day 3 cont.) Question # 2: About how tall is the classroom ceiling, 3-4 m, 5-6 m or 7-8 m?

79. Benchmark Metre Reinforcement (Day 3 cont.) Answer:

80. Benchmark Metre Reinforcement (Day 3 cont.) Question # 3: About how wide is the class room, 5- 6 m, 10-12 m or 19-20 m?

81. Benchmark Metre Reinforcement (Day 3 cont.) Answer:

82. Benchmark Metre Reinforcement (Day 3 cont.) Question # 4: About how wide is the projection screen in the classroom, 2-3 m, 5-6 m or 8-9 m?

83. Benchmark Metre Reinforcement (Day 3 cont.) Answer:

84. Benchmark Metre Reinforcement (Day 3 cont.) Question # 5: About how tall is a book shelf, 1-2 m, 3-4 m, or 5-6 m?

85. Benchmark Metre Reinforcement (Day 3 cont.) Answer:

86. END OF LESSON

87. Benchmark Metre Reinforcement (Day 4) Question # 1: About how many metres wide is the white board?

88. Benchmark Metre Reinforcement (Day 4 cont.) Answer:

89. Benchmark Metre Reinforcement (Day 4 cont.) Question # 2: About how many metres tall is the white board?

90. Benchmark Metre Reinforcement (Day 4 cont.) Answer:

91. Benchmark Metre Reinforcement (Day 4 cont.) Question # 3: About how many metres is the office from your classroom door?

92. Benchmark Metre Reinforcement (Day 4 cont.) Answer:

93. Benchmark Metre Reinforcement (Day 4 cont.) Question # 4: About how many metres wide is the classroom?

94. Benchmark Metre Reinforcement (Day 4 cont.) Answer:

95. Benchmark Metre Reinforcement (Day 4 cont.) Question # 5: About how many metres tall is the classroom ceiling?

96. Benchmark Metre Reinforcement (Day 4 cont.) Answer:

97. END OF LESSON

98. Benchmark Metre Assessment (Day 5) Question # 1: Is your classroom 5 m, 10 m, or 20 m wide?

99. Benchmark Metre Assessment (Day 5 cont.) Answer:

100. Benchmark Metre Assessment (Day 5 cont.) Question # 2: About how wide is the projection screen in the classroom, 2-3 m, 5-6 m or 8-9 m?

101. Benchmark Metre Assessment (Day 5 cont.) Answer:

102. Benchmark Metre Assessment (Day 5 cont.) Question # 3: About how many metres tall is the classroom ceiling?

103. Benchmark Metre Assessment (Day 5 cont.) Answer:

104. Benchmark Metre Assessment (Day 5 cont.) Question # 4: About how many metres wide is your desk?

105. Benchmark Metre Assessment (Day 5 cont.) Answer:

106. Benchmark Metre Assessment (Day 5 cont.) Question # 5: About how many metres tall is the classroom door?

107. Benchmark Metre Assessment (Day 5 cont.) Answer:

108. END OF LESSON

109. Measurement Estimation – Length Summative Assessment Question # 1: About how wide is the projection screen in the classroom, 2-3 m, 5-6 m or 8-9 m?

110. Measurement Estimation – Length Summative Assessment Answer:

111. Measurement Estimation – Length Summative Assessment Question # 2: About how tall is a waste basket?

112. Measurement Estimation – Length Summative Assessment Answer:

113. Measurement Estimation – Length Summative Assessment Question # 3: About how many metres is the office from your classroom door?

114. Measurement Estimation – Length Summative Assessment Answer:

115. Measurement Estimation – Length Summative Assessment Question # 4: Is a piece of lined paper 20 – 30 cm wide or 40 – 50 cm wide?

116. Measurement Estimation – Length Summative Assessment Answer:

117. Measurement Estimation – Length Summative Assessment Question # 5: Is the top of your desk more, less, or about 30 cm wide?

118. Measurement Estimation – Length Summative Assessment Answer:

119. END OF LESSON