Lesson 6.1 · Measurement and Time
Ordering by length
Which pencil is longer? Which rope is shortest? You can answer these questions by looking closely and lining things up.
Line them up
To compare two things, put their ends together at the same starting line. Then look at the other end. The one that sticks out farther is longer. The other one is shorter.
Longest to shortest
Line up the ends at the same start. The one that reaches farthest is the longest. The one that stops first is the shortest. The one in between is in the middle.
Worked example: Three ribbons
Each ribbon starts at the same line.
🟥🟥🟥🟥🟥 red
🟦🟦 blue
🟩🟩🟩🟩 green
The red ribbon reaches farthest, so red is longest. Blue stops first, so blue is shortest. Green is in the middle.
Longest to shortest: red, green, blue.
Compare using a third thing
Sometimes you can't put two things side by side. A couch can't move next to a door! Use a third thing, like a string, to help.
Worked example: The string trick
Mia's string is longer than her desk. The same string is shorter than the rug.
So which is longer, the desk or the rug?
The desk is shorter than the string. The rug is longer than the string. So the rug is longer than the desk.
Worked example: Who is tallest?
Ben is taller than Ava. Ava is taller than Leo.
Ben is taller than Ava, and Ava is taller than Leo. So Ben is taller than Leo too.
Tallest to shortest: Ben, Ava, Leo.
Common mistake
Always start at the same line! If one thing starts farther ahead, it can look longer even when it isn't.
Practice
Which snake is longer? Both start at the same line.
🟨🟨🟨 yellow snake
🟪🟪🟪🟪🟪🟪 purple snake
Which crayon is the shortest? They all start at the same line.
🟧🟧 orange
🟦🟦🟦🟦 blue
🟥🟥🟥 red
Put the sticks in order from longest to shortest.
🟫🟫🟫 stick A
🟫🟫🟫🟫🟫🟫 stick B
🟫 stick C
Look at the lines. They all start at the same place.
Which line is the longest?
The bat is longer than the broom. The broom is longer than the spoon. Which is the shortest?
Kim's yarn is longer than her book. The same yarn is shorter than her bed. Which is true?
Zoe is taller than Max. Max is taller than Jay. Put them in order from tallest to shortest.