🔢 MathGrade 2Lesson 5
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Find Number Patterns

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Learning Objectives

  • 1Identify the rule in a number sequence
  • 2Find the missing numbers in patterns that count by 2s, 5s, 10s, and 100s
  • 3Apply the rule to counting-forward and counting-backward patterns
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Mini Lesson

A number pattern is a list of numbers that follow a rule — you add or subtract the same amount each time. Find the rule and you can fill any gap!

How to find the rule

  • Look at two numbers next to each other and subtract: bigger minus smaller equals the rule.
  • Check the rule works for every pair in the sequence.
  • Example: 14, 16, 18, 20 — each pair differs by 2, so the rule is +2.

Common patterns

  • Count by 2s: 4, 6, 8, 10, 12...
  • Count by 5s: 25, 30, 35, 40, 45...
  • Count by 10s: 130, 140, 150, 160...
  • Count by 100s: 200, 300, 400, 500...

Counting-back patterns

  • The rule can also subtract: 50, 45, 40, 35 — the rule is -5.
  • Use the same method — find the difference between neighbors, then apply it backwards.
Four common number patternsFour rows showing: count by 2s: 4, 6, 8, 10; count by 5s: 25, 30, 35, 40; count by 10s: 130, 140, 150, 160; count by 100s: 200, 300, 400, 500.Common Patterns+246810...+525303540...+10130140150160...+100200300400500...Each row adds the same amount every time.
Four pattern strips showing +2, +5, +10, and +100 sequences with their starting numbers.
Finding the missing number in a patternThe sequence 45, blank, 55, 60. Step 1: find the rule by subtracting 55 from 60 equals 5. Step 2: subtract 5 from 55 equals 50. The missing number is 50.Find the Missing Number45?5560Step 1: Find the rule60 − 55 = 5 → rule is +5Step 2: Work backwards55 − 5 = 50 → missing number is 5045, 50, 55, 60
Two steps to find the missing number in 45, ?, 55, 60 — find the rule (+5), then count back from 55 to get 50.
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Ask yourself: "What is the difference between each pair of numbers? Is the pattern going up or going down?"

Vocabulary
Pattern
A list of numbers that follow a rulee.g. 5, 10, 15, 20 is a pattern that adds 5 each time.
Rule
What you add or subtract each time in a patterne.g. The rule for 50, 45, 40 is subtract 5.
Sequence
An ordered list of numberse.g. I filled in the missing number in the sequence.
Skip count
Counting by jumps of the same number, like 2s or 5se.g. I skip count by 5s: 5, 10, 15, 20.
Difference
The amount between two neighboring numberse.g. The difference between 14 and 16 is 2.
Increase
To go up by a certain amounte.g. The numbers increase by 10 each step.
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← Lesson 4: Compare and Order 3-Digit NumbersLesson 6: Identify Odd and Even Numbers →