Grade 4 Patterns: Pattern Rules

Worked examples

Real problems from the practice worksheets, solved one step at a time.

1. Example 1

   3813?23?

   Fill in the missing terms

   1. Compare numbers that sit next to each other: 3 → 8 is +5, 8 → 13 is +5.
   2. The rule is add 5: each number is 5 more than the one before.
   3. Use the rule to fill the blanks: 13 + 5 = 18 (check: 18 + 5 = 23, the next number ✓); 23 + 5 = 28.
   4. So the missing numbers are 18, 28.

   Answer: 18, 28

2. Example 2

   91317?25?

   Fill in the missing terms

   1. Compare numbers that sit next to each other: 9 → 13 is +4, 13 → 17 is +4.
   2. The rule is add 4: each number is 4 more than the one before.
   3. Use the rule to fill the blanks: 17 + 4 = 21 (check: 21 + 4 = 25, the next number ✓); 25 + 4 = 29.
   4. So the missing numbers are 21, 29.

   Answer: 21, 29

3. Example 3

   1611?21?

   Fill in the missing terms

   1. Compare numbers that sit next to each other: 1 → 6 is +5, 6 → 11 is +5.
   2. The rule is add 5: each number is 5 more than the one before.
   3. Use the rule to fill the blanks: 11 + 5 = 16 (check: 16 + 5 = 21, the next number ✓); 21 + 5 = 26.
   4. So the missing numbers are 16, 26.

   Answer: 16, 26