Learning Resources

Investigation 1: Fitness Foray

Step B: 

One strategy for summing the terms of an arithmetic sequence is pairing up terms at each end of the sequence, moving inward to form pairs. The sums are equal and the number of pairs is half the number of terms. The pairs of numbers that should be added here are shown below.

=  60       +     60        +    60        +    60        +    60        +    60        +    60

=  7(60)

=  420  

Note: This sum is double the total of the times for 7 days, since each time is listed twice. Thus, the actual sum for 7 days can be written as ½(7 x 60).