SME
Grade 2 Math · Problem type
Use a number line to add and subtract lengths
Use this for “A 35 cm ribbon and a 20 cm ribbon end to end: how long are they together?”
Picture
This is an example. Type the numbers from your problem to start.
First length (cm)
+
Second length (cm)
=
Total length (cm)
Number sentences
35 + 20 = 55
Good to know
•
Put two lengths end to end. Add them to find the total length.
•
On a number line, start at 0. Jump the first length. Then jump the second.
•
Use the same unit for both lengths.
Step-by-step
WE KNOW
First length: 35 cm
Second length: 20 cm
FIND
total length
Step 1 · Find total length
35 + 20 = ?
Start at the first length. Jump the second length. Read where you land.
Total length: 55 cm
Check
Put the numbers back in. Both sides should match.
35 + 20 = 55 ✓
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.
Refresh
Related lessons
Measure length in inches, feet, centimeters and meters
Main lesson
Broken ruler
Use this when the object doesn’t start at 0 on the ruler.
Relate inches and feet
Use this to measure the same object in feet and in inches.
Relate centimeters and meters
Use this to measure the same object in meters and in centimeters.
Choose the unit
Use this to choose centimeters or meters for a crayon, a door or a hallway.
Estimate lengths
Use this for “About how long is a crayon: 1 centimeter, 10 centimeters or 1 meter?”