Patterns in Numbers

What are the missing numbers in this pattern?
12, 15, ___, 21, ____, 27

• 18,23
• 18, 24
• 17, 25
• 17, 24

Which shows the pattern counting by 3s?

• 3,6,8,11

• 1,4,7,10

• 2,4,6,8

• 3,5,7,9

Describe the pattern.

4,7,10,13,16

• decrease by 3

• decrease by 2

• increase by 3

• increase by 4

3, 5, ___, 9, 11

• 6

• 7

• 8

• Not sure

20, 30, ___, 50, 60

• 30

• 50

• 40

• 04

What comes next in the pattern?

• acorn
• pumpkin

∆∇∆∇∆∇∆∇__

• ∆
• ∇

How many counters would come next?

• 5
• 7
• 9
• 11

∎∆∆∎ΔΔ__

• ∎
• Δ

What is the problem with this pattern? 
2, 4, 6, 9

• Nothing is wrong
• The 9 should be an 8
• The pattern stopped too soon