An arithmetic sequence (sometimes called a “progression”) is a particular type of sequence that has an initial value, as with all sequences. A proper arithmetic sequence has a common difference, that when added to the initial number and each consecutive number, provides the arithmetic sequence. An arithmetic sequence may begin with a negative number as long as the sequence increases from that value. Arithmetic sequences are non-random, yielding a method for their continuation.

An arithmetic sequence example would look like this:

1, 5, 9, 13, 17, 21, 25, 29, … with a common difference of 4.

Look for the common difference by subtracting the preceding value from the current value and ensuring this holds for the following numbers.



Is this sequence an arithmetic sequence? 2, 1, 3, 4, 7, 11, ….

Assign "yes" or "no" to checkpoint_1.


If we have 1, 4, 7, 10, 13, 16, 19, 22, 25, …, what is the number following “25?”

Assign the answer to checkpoint_2.

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