how do you figure out the pattern of 1,4,9,16?

1 + 3 = 4

4 + 5 = 9
9 + 7 = 16

16 + ____ = 25

Do you see the pattern?

16+9=25

Answer is 9

how about

1^2 = 1
2^2 = 4
3^2 = 9
4^2 = 16
etc

Ahh -- thank you, Reiny. I didn't think of squares.

To figure out the pattern of a sequence, you need to observe the numbers and look for a relationship or rule that connects them. In this case, the sequence is 1, 4, 9, 16.

One approach is to analyze the differences between consecutive terms. Let's calculate the differences between each pair of consecutive terms:

4 - 1 = 3
9 - 4 = 5
16 - 9 = 7

By observing the differences, you can see that they are increasing by 2 each time. Starting with 3, then 5, and finally 7. This indicates that the original sequence may be the result of adding consecutive odd numbers.

To verify this, let's start with the first term, 1, and incrementally add consecutive odd numbers: 1, 1+3=4, 4+5=9, 9+7=16. As you can see, the pattern holds.

Thus, the pattern of the sequence 1, 4, 9, 16 is the result of squaring consecutive natural numbers: 1^2 = 1, 2^2 = 4, 3^2 = 9, 4^2 = 16.

By understanding how to analyze the differences and test relationships between consecutive terms, you can solve various types of pattern questions.