To find the "Factor Rainbow" for the number 20, we need to find all the pairs of whole numbers that multiply together to make 20. We start with 1 and work our way up.
Step 1: Start with 1
Does 1 go into 20? Yes.
$1 \times 20 = 20$
So, our first pair is
1 and 20.
Step 2: Try 2
Does 2 go into 20? Yes, because 20 is an even number.
$2 \times 10 = 20$
So, our second pair is
2 and 10.
Step 3: Try 3
Does 3 go into 20? Let's check: $3 \times 6 = 18$ and $3 \times 7 = 21$. Since 20 is in between, 3 does not divide evenly into 20. So, we skip 3.
Step 4: Try 4
Does 4 go into 20? Yes.
$4 \times 5 = 20$
So, our third pair is
4 and 5.
Step 5: Try 5
We already found 5 in the previous step ($4 \times 5$). When we reach a number that is already part of a pair we found, we are done.
The Factors:
The factors of 20 are: 1, 2, 4, 5, 10, 20.
Drawing the Rainbow:
In a factor rainbow, you connect the pairs with arcs from smallest to largest:
- The outermost arc connects
1 and 20.
- The next arc connects
2 and 10.
- The innermost arc connects
4 and 5.
Final Answer:
The factor pairs for 20 are (1, 20), (2, 10), and (4, 5).
Parent Tip: Review the logic above to help your child master the concept of factor rainbow worksheet.
