Topic 8 of 8
Comparing length and weight
Step 2 · Numbers to 100 topics
Say which of two things is longer or shorter, heavier or lighter, and compare them fairly.
Longer and shorter
Length is how long something is. Put two things side by side to see which is longer and which is shorter.
Measuring with cubes or paper clips tells you how much longer. The pencil is 6 cubes and the crayon 4 cubes, so the pencil is 2 cubes longer.
Heavier and lighter
Weight is how heavy something is. Hold one thing in each hand, or use a balance scale. The side that goes down holds the heavier thing.
Big things are not always heavy. A beach ball is big but light. A small rock can be heavy.
Comparing fairly
A fair comparison of length starts both things at the same line. If one thing starts further along, it can look longer when it is not.
When you measure, use the same unit for both things, with no gaps and no overlaps.
Example: How much longer
A ribbon is 5 clips long. A string is 8 clips long. Which is longer, and by how much?
- Both were measured with the same clips.
- 8 is more than 5, so the string is longer.
- Count on from 5 to 8: three more.
AnswerThe string, by 3 clips
Try it yourself
Work each one on paper first, then open the answer to check.
A rope is 9 clips long and a ribbon 6 clips long. Which is shorter?
Show answer
The ribbon.
On a balance, the side with the apple goes down. Which is heavier, the apple or the grape on the other side?
Show answer
The apple.
A pencil is 7 cubes long and a crayon 4 cubes long. How much longer is the pencil?
Show answer
3 cubes.
Is a big balloon always heavier than a small stone?
Show answer
No. A balloon is big but light.
Why should two things start at the same line when you compare their lengths?
Show answer
So the comparison is fair: then the end that sticks out further belongs to the longer thing.