Telling Time and Measuring Length: Grade 1 Study Guide
Measurement uses units. Children first compare, then measure with small objects, then learn clocks.
Grade 1 children learn to order three objects by length and to measure a length using a smaller object as a unit, such as paper clips or cubes. The object is laid end to end with no gaps and no overlaps. The number of units tells how long it is: 'The pencil is 7 cubes long.'
They also learn to tell and write time in hours and half-hours using analog and digital clocks, and to organize simple data with up to three categories.
Measuring with units
Line up the start of the object with the start of the unit row. If a crayon is 6 paper clips long, a longer object will take more clips. If two people use different units (paper clips and cubes), they get different numbers, which shows why we need standard units like inches and centimeters (introduced in Grade 2).
A cube or a paper clip.
No gaps and no overlaps.
Say it as 'about 6 cubes long'.
Which object is longer?
Telling time
An analog clock has a short hour hand and a long minute hand. At an o'clock time, the minute hand points straight up at 12 and the hour hand points to the hour: 3:00 is 'three o'clock'. At half past, the minute hand points straight down at 6 and the hour hand is halfway between two numbers: 3:30.
| Time | Minute hand | Hour hand | Digital |
|---|---|---|---|
| Three o'clock | At 12 | At 3 | 3:00 |
| Half past three | At 6 | Between 3 and 4 | 3:30 |
| Seven o'clock | At 12 | At 7 | 7:00 |
| Half past ten | At 6 | Between 10 and 11 | 10:30 |
Simple data
Sort objects and count each group to make a tally chart or picture graph. If 5 children like apples, 3 like bananas and 2 like grapes, apples is the most popular and grapes the least. You can say how many more or fewer: apples has 2 more than bananas.
Worked examples and common mistakes
Example: The hour hand is on 5 and the minute hand on 12. It is 5:00. Example: A book is 9 cubes long and a pencil is 7 cubes long. The book is 2 cubes longer. Common mistakes: mixing up the hands, writing half past 4 as 4:06 (the minute hand pointing to 6 means 30 minutes) and leaving gaps between units. Practise with a big clock where the hands can be moved.
Check your understanding: model answers
1. The minute hand points to 6 and the hour hand sits between 8 and 9. Digital: 8:30. 2. 9 − 4 = 5 clips longer. 3. 6 − 4 = 2 more.
✨ Key Takeaways
- Measure length by laying equal units end to end.
- The hour hand is short; the minute hand is long.
- At o'clock the minute hand is at 12; at half past it is at 6.
- Tally charts help us compare groups.
💬 Questions for Discussion & Reflection
- Show 8:30 on a clock and write it as digital time.
- A leaf is 4 clips long and a stick is 9 clips long. How much longer is the stick?
- In a tally, 6 chose red, 4 blue. How many more chose red?
Print graph paper for charts →