Arithmetic, geometric or neither? Find the next terms with a recursive rule
Grade 9 Math Worksheet
Circle the best answer, or write your answer on the line.
Ari's phone-tree chart for a club picnic shows the list 4, 12, 36, 108. Is the list arithmetic, geometric or neither?
- Neither: the arrows change
- Geometric: × 3 on every arrow
- Arithmetic: + 8 on every arrow
Esme's bake-sale tally shows the list 2, 6, 18, 30. Is the list arithmetic, geometric or neither?
- Arithmetic: + 4 on every arrow
- Geometric: × 3 on every arrow
- Neither: the arrows change
Jun's math-club handout shows the list 81, 27, 9, 3. Is the list arithmetic, geometric or neither?
- Arithmetic: − 54 on every arrow
- Neither: the arrows change
- Geometric: × 1/3 on every arrow
Kira zooms in on a seed picture again and again. Its width on screen, in mm, is 2, 10, 50, 250. What is the next term?
Noah's robot token jumps the same amount each turn on a number line. Its spots are 14, 9, 4, -1. What is the next term?
Ren climbs a pretend number ladder. The rule is a(1) = 6, a(n) = a(n − 1) + 9. What is a(5)?
Ari draws a tree whose branches split. The rule is a(1) = 4, a(n) = 3 · a(n − 1). What is a(5)?
Esme's school hall has 14 chairs in row 1, and each row has 2 more chairs than the row before. How many chairs are in row 8?
A science video shows 300 bacteria in a dish at count 1. The number doubles (× 2) at each count, 20 minutes apart. How many bacteria does Kira see at count 5?
Luz drops a play ball from shoulder height. Bounce 1 reaches 80 cm, and each bounce is 1/2 as high as the one before. How high, in cm, is bounce 4?