4 + 5 is almost a double. It is 4 + 4 with one more.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Start from what you know
You know 4 + 4 = 8. So 4 + 5 must be 9.
4 and 5 makes 9.
First part
Second part
Why leaning on a double works
6 + 7 is 6 + 6 with one extra. You are turning an unknown fact into a known one plus a small adjustment.
The move is bigger than doubles
Start from something you know, then adjust. You will use that same move for the rest of mathematics.
Step 2: Try It Yourself
Tap and try it out.
3 and 4 makes 7.
Step 3: Watch an Example
One step at a time.
Watch Leo Use a Double
Leo works out 3 + 4.
- Step 1
He notices it is nearly 3 + 3.
Step 4: Your Turn
Practice makes it stick.
Cookie Jar
Problem 1 of 1
Mia has 4 cookies. Ben has 5. How many cookies altogether?
Nearly a Double
Find the double first, then add one.
1 of 2
2 + 3 = ?
2 of 2
4 + 5 = ?
Step 5: Quick Check
Show what you know.
Question 1 of 2
3 + 4 = ?
Question 2 of 2
5 + 4 = ?
What You Learned
- Some sums are nearly doubles.
- Use the double you already know.
- Then add one more.