Skip to lesson

Math · Grade 1 Math

Chapter 6: Measuring Length and Reading Data

Longer Than, Shorter Than

Line them up at the same end first.

Lesson
1
Time
About 10 minutes
WorksheetAnswer key
0 of 4 done

Step 1: Let's Learn

Read it, or press Listen and follow the words.

To compare two things, line up one end. Then look at the other end.

This part matters

If the ends do not line up, you cannot tell which is longer.

Red ribbon
Blue ribbon

Red ribbon is 2 cubes longer than Blue ribbon.

Red6
Blue4

Why the ends must line up

If one starts further forward it looks longer without being longer. Lining them up removes everything except the length.

A fair test changes one thing only

Same starting line, same direction. Then any difference you see is a real difference.

Step 2: Try It Yourself

Change the lengths and read the sentence.

Change either ribbon. They always start at the same edge.
Red ribbon
Blue ribbon

Red ribbon is 2 cubes longer than Blue ribbon.

Step 3: Watch an Example

One step at a time.

Watch Ana Compare

Ana has a red pencil and a blue pencil.

  1. Step 1

    She puts both ends level at the bottom.

Step 4: Your Turn

Practice makes it stick.

Two Sticks

Problem 1 of 1

A red stick is 8 cubes long. A blue stick is 5 cubes. Which is longer?

Make Them Match

Try to make both ribbons exactly the same length.

Red ribbon
Blue ribbon

Blue ribbon is 5 cubes longer than Red ribbon.

Step 5: Quick Check

Show what you know.

Question 1 of 2

Why must you line up one end before comparing?

Question 2 of 2

A rope is 9 cubes. A string is 6 cubes. How much longer is the rope?

What You Learned

  • Line up one end before you compare.
  • Then look at the other end.
  • The one that sticks out further is longer.