Download expanded Chapter 10 student textbook (PDF, updated edition). The earlier shorter textbook edition remains available below.
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Grade 3 Mathematics, Chapter 10: Measurement, Time, and Data
Read lessons | Daily exercises | Teacher answers | Grade 3 index
Read each day’s teaching and worked example before completing the corresponding exercises. This chapter is one part of a developing curriculum, not the complete school year.
Day 1: Measure Length
Learn: Length tells how far one point is from another. A ruler has equal-sized marks. Start at zero, not the ruler’s outside edge. One centimeter is smaller than one meter; 100 centimeters make one meter. Measure to the nearest marked centimeter.
Worked example: A ribbon begins at 0 cm and ends at 14 cm, so it is 14 cm long.
Day 2: Tell Time to the Minute
Learn: An analog clock has a short hour hand and a longer minute hand. Each large number marks five minutes; count small marks for individual minutes. The hour hand moves gradually between numbers.
Worked example: At 3:25, the minute hand points to 5 and the hour hand is between 3 and 4.
Day 3: Elapsed Time
Learn: Elapsed time is the amount of time between a start and an end. Move forward on a clock or time line in chunks of hours and minutes. Check whether the event crosses noon or midnight.
Worked example: From 9:20 to 10:05 is 40 minutes to 10:00 and 5 more minutes, or 45 minutes.
Day 4: Measure and Graph Data
Learn: Collect measurements in the same unit. A scaled bar graph uses a consistent scale, and labels identify categories and units. Do not compare bar heights if scales are different.
Worked example: Plants A, B, and C measure 6, 9, and 4 cm. Plant B is 5 cm taller than C.
Day 5: Independent Measurement Check
Learn: Complete without coaching; show units, number-line jumps, and the scale of a data graph. These questions check selected skills, not the full grade-level standards.
Worked example: Answer and explain each result.
Expanded teaching and guided reasoning
Use these extended explanations alongside the five-day lessons and downloadable chapter PDF. The expanded teaching is now available in the updated PDF linked at the top of this page. Parent or teacher guidance remains important.
Extended Day 1: Ruler reading and unit choice
Place the zero mark at the starting point. If an object starts at 2 cm and ends at 13 cm, subtract 13 – 2 to find its length: 11 cm. Counting the end mark as an extra centimeter is a common error. Compare two objects by measuring them with the same unit.
A classroom table might be 120 cm long, or 1 m 20 cm. A table measuring 120 meters would be longer than a football field and is unreasonable. Estimate first, then measure.
Try it: A line spans the 3 cm to 17 cm marks. Its length is 14 cm, not 17 cm. Explain why subtraction is necessary.
Extended Day 2: Reading an analog clock
The long hand counts minutes. At the 1 it shows 5 minutes, at the 6 it shows 30, and at the 9 it shows 45. The short hand moves gradually between hour marks. At 4:45 it is close to 5, but the hour is still 4.
Use two number lines. One counts hours 1 through 12. Another counts minutes in increments of five. At 7:38, count 35 minutes at the 7, then three extra minute marks.
Try it: At 2:50, where are the hands? The minute hand points to 10, and the hour hand is almost at 3. Do not call the hour 3 yet.
Extended Day 3: Elapsed time by breaking apart intervals
To find the interval from 1:47 to 2:23, jump from 1:47 to 2:00 (13 minutes), then from 2:00 to 2:23 (23 minutes). Total: 13 + 23 = 36 minutes. Show the jumps so another person can check.
To find an ending time, move forward instead: 9:55 plus 20 minutes is 10:15. Cross the hour carefully rather than treating the minutes like base-100 numbers.
Try it: A reading block begins at 10:35 and ends at 11:10. Count 25 minutes to 11:00 and another 10 minutes. Total: 35 minutes.
Extended Day 4: Making an honest scaled graph
Give the graph a title, label the categories and measurement unit, and use equal intervals on the vertical axis. If one square represents 2 cm, a measurement of 8 cm needs four squares. Changing the scale midway misleads readers.
Example plant lengths: A is 4 cm, B is 10 cm, C is 6 cm. A bar graph with 1 square = 2 cm uses bar heights of 2, 5, and 3 squares. The greatest difference is 10 – 4 = 6 cm.
Try it: For a new set of data, draw a graph and write the key or scale. Ask a partner to retrieve the measurements from the graph without seeing the original table.
Extended Day 5: Independent check and corrections
Before handing in the Day 5 workbook, check that every measurement has a unit, every interval counts minutes correctly, and any graph includes a consistent scale. This day is designed to reveal misunderstandings, not to provide the learner with an example to copy.
If an answer seems impossible, estimate again. Three meters should be hundreds of centimeters, not three centimeters. Thirty-five minutes after 11:40 passes noon and becomes 12:15.
Self-check prompt: What did you do when crossing an hour? Which evidence supports the data comparison? Leave an explanation in writing.
Curriculum status: Supplemental instructional development, not a completed full-year textbook or verified standards-mastery certification.