TEACHER ABI PSHS NCE · QUANTITATIVE ABILITY
Patterns, Sequences, and Number Relationships
Spot how numbers change, find the rule, and predict what comes next without checking every possible answer.
Arithmetic patternsGrowing patternsMissing termsQuick Fire + Mastery
MY STATUS
Patterns, Sequences, and Number Relationships
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START HERE
Ask: what changes each time?
Sequence = numbers arranged in an order that follows a rule.
Same difference:
5, 9, 13, 17
Add 4 each time.
5, 9, 13, 17
Add 4 each time.
Same factor:
3, 6, 12, 24
Multiply by 2 each time.
3, 6, 12, 24
Multiply by 2 each time.
Changing difference:
2, 5, 9, 14
Add 3, then 4, then 5.
2, 5, 9, 14
Add 3, then 4, then 5.
Alternating rule:
4, 7, 14, 17, 34
+3, ×2, +3, ×2.
4, 7, 14, 17, 34
+3, ×2, +3, ×2.
FAST METHOD
Check the gaps first
- Subtract neighboring terms. Are the differences the same?
- If not, check whether the differences themselves follow a pattern.
- Check simple multiplication or division.
- If neither works, test an alternating rule.
- Use the simplest rule that explains every term.
WORKED EXAMPLES
Six common pattern types
1. Same difference
12, 17, 22, 27, ?Add 5 each time.
32
2. Same factor
2, 6, 18, 54, ?Multiply by 3 each time.
162
3. Growing differences
4, 7, 11, 16, 22, ?Differences are +3, +4, +5, +6. Next is +7.
29
4. Alternating operations
5, 10, 12, 24, 26, ?×2, +2, ×2, +2, so next is ×2.
52
5. Square numbers
1, 4, 9, 16, 25, ?These are 1², 2², 3², 4², 5².
36
6. Missing middle term
8, 13, ?, 23, 28Add 5 each time.
18
TRY WITH ME
Use the gaps
Find the next number:
3, 7, 12, 18, 25, ?- Find the differences: +4, +5, +6, +7.
- The difference increases by 1 each time.
- Next difference is +8.
33
COMMON TRAPS
Watch out for these
Guessing from only the first two terms.
The rule must fit the whole sequence.
The rule must fit the whole sequence.
Missing an alternating pattern.
Try checking odd-position and even-position steps separately.
Try checking odd-position and even-position steps separately.
Forcing a complicated rule.
Entrance tests usually reward the simplest consistent pattern.
Entrance tests usually reward the simplest consistent pattern.
Ignoring changing differences.
If the first differences are not equal, inspect how they change.
If the first differences are not equal, inspect how they change.
REGULAR PRACTICE
Build the skill
QUICK FIRE
Can you spot the rule fast?
Question 1 of 5
FRESH MASTERY CHECK
Can you do it without hints?
Score 5/5 to verify this competency.
NEED HELP?
Can't see the pattern yet?
Send Teacher Abi the sequence. I can help you test the differences, factors, and alternating rules without giving away the method too early.
Message Teacher AbiPSHS NCE REVIEW PATH
Choose your next step
Next competency: Counting, Data, and Probability
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