The difference is the extra bit that sticks out past the shorter one.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Count the extra
Line them up, then count only the part that sticks out.
The difference is the extra bit
Line them up at one end. Whatever sticks out past the shorter one is the difference, and it can be measured on its own.
That is subtraction
Comparing lengths is the same question as finding a missing part. Ten cubes and seven cubes differ by three.
Step 2: Try It Yourself
Tap and try it out.
Snake
8
Worm
3
Snake is 5 cubes longer than Worm.
Step 3: Watch an Example
One step at a time.
Watch Ben Find the Difference
Ben has an 8-cube snake and a 3-cube worm.
- Step 1
He lines them up at the same end.
Step 4: Your Turn
Practice makes it stick.
Two Trains
Problem 1 of 2
A red train is 9 cubes. A blue train is 6 cubes. How much longer is the red one?
Jumping
Problem 2 of 2
Ana jumps 7 cubes. Leo jumps 4. How much further did Ana jump?
How Much Longer?
Find the extra bit.
1 of 2
10 cubes and 6 cubes. How much longer?
2 of 2
8 cubes and 5 cubes. How much longer?
Step 5: Quick Check
Show what you know.
Question 1 of 2
A 9-cube stick and a 4-cube stick. How much longer is the first?
Question 2 of 2
Two ribbons are both 6 cubes. How much longer is one than the other?
What You Learned
- The difference is the extra bit.
- Line them up, then count what sticks out.
- If they are the same, the difference is 0.