Math CalculatorsRoster · Regions · Venn

Set Intersection Calculator

2026-09-29 8 min

Shared elements present in both A and B.

Shared elements present in both A and B.

Grade level
6–12
Curriculum band
Difficulty
Beginner
For this topic
Time to master
1 week
With daily practice
Tools on page
10 on page
Calculator + practice
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Calculator

Rosters — Set Intersection Calculator

Set A (comma separated)
Set B (comma separated)
Results update live as you type
Status:Computed — see roster

Result Summary

Headline{3, 4}

Results

Optimal

Headline

{3, 4}

Roster or verdict

Roster parsing dedupes exactly; Venn regions tile the union; display caps at 24 shown.

Statistics

Live readouts from your current rosters.

Answer size

2

{3, 4}

Visualizations

Region sizes

0only A
0both
0only B

Overlap share

both / union0%

Formula

Shared elements present in both A and B.

A ∩ B = {x : x in A and x in B}

Alternative Form

Subset of both parents

Variables

SymbolNameUnitDescription
A, BInput setsrostersDeduped element lists
resultAnswer rosterrosterOperation output

Explanation

Membership decides everything: test each element once against the defining rule.

Derivation

Union adds memberships; intersection ANDs them; difference negates; De Morgan dualizes under complements.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Parse rosters; dedupe while preserving first order.

Result: Sets parsed
Step 2

Apply the set operation element by element.

A ∩ B = {x : x in A and x in B}
Result: {3, 4}
Step 3

Count regions for the Venn diagram.

Result: Regions sized
Step 4

Cross-check with the counting identity.

Subset of both parents
Result: Check passed
Step 5

Format the roster with cap 24 shown.

Result: Display ready
Step 6

State the finished answer.

Result: {3, 4}
Final Answer
{3, 4}

Worked Examples

See how the calculator works with different scenarios.

Scenario

A = {1,2,3,4}, B = {3,4,5,6}.

Inputs

A:1,2,3,4
B:3,4,5,6

Calculation

Union {1..6}; both {3,4}

Result

See live roster

Interpretation

Overlap of two drives all regions.

Understanding Your Result

Your Result: Headline: {3, 4}

Typical range: Sizes from 0 (empty) up; Venn regions tile the universe.

What This Means

The headline roster lists exactly the elements satisfying the stated rule — nothing more.

Why It Matters

Filters, joins, permissions and logic gates are set operations in disguise.

Professional Interpretation

Read the missing list for subset verdicts; read neither for coverage gaps.

Recommendations

  • •Dedupe inputs first
  • •Fix the universe for complements
  • •Draw the Venn before coding filters

Learn — The Complete Guide

Set Intersection Calculator applies one membership rule to your rosters with Venn proof.

The core concept

Sets are predicates: union ORs, intersection ANDs, complement NOTs.

  • Membership decides all
  • Venn regions tile U
  • Complements need U

Derivations — why the formulas work

Why union adds then subtracts

  1. 1Count A
  2. 2Count B
  3. 3Both counted twice — subtract once

Where you meet this in real life

▸Database joins
▸Search filters
▸Permissions
▸Logic design
▸Search filters
▸Database joins
▸Access control
▸Circuit logic

Learn this first — prerequisites in order

  1. 1Listing
  2. 2Venn reading
  3. 3Multiples

Careers that use this daily

  • •Analyst — filters
  • •Engineer — queries
  • •Designer — logic
  • •Admin — permissions

Why it helps

  • •Live Venn feedback
  • •Roster plus counts
  • •De Morgan verification

Best practices

  • •Fix U first
  • •Keep labels consistent
  • •Check neither for coverage

Limitations — what this tool does not do

  • •Finite rosters only
  • •Text equality (case-sensitive)

Curriculum map — where this topic lives in school

LevelGradesStandardsSkills
Middle school6–86.SPRosters · Venn
High school9–12HSS-CPOperations · De Morgan

Timeline — how this idea grew up

  1. 1874

    Cantor sets

    Set theory founded.

  2. 1880

    Venn diagrams

    Visual logic published.

A little history

  • • De Morgan (1847) dualized AND/OR.
  • • Zermelo-Fraenkel axiomatized sets.

Exam-day checklist

  • • Draw circles
  • • Label neither
  • • Sum-check regions

Myths vs facts

Myth: Order matters in sets.
Truth: {1,2} = {2,1} — only membership counts.
Myth: A minus B equals B minus A.
Truth: Difference is directional.

Practical Tips

  • •Comma-separate values
  • •Duplicates auto-collapse
  • •Fix U for complements
  • •Read neither last
  • •Copy with share bar

Common Mistakes

Case-mismatched labels
Apple vs apple differ — normalize first.
Missing universe
Complements need U stated.
Reading difference backwards
A-B keeps A-only elements.

Assumptions

This calculator makes the following assumptions to provide estimates:

Finite rosters: Explicit element lists.
Text equality: Exact trimmed match.
Order-free: First-seen order for display.

Limitations

Be aware of these limitations when using this calculator:

No infinite sets: Builder page covers ranges.
Roster caps: 24 shown; counts complete.

Frequently Asked Questions

Answers to common questions about this calculator.

Disjoint sets?
Intersection empty: ∅.
Use?
Common members, shared filters.
How do I enter sets?
Comma-separated values; duplicates collapse automatically and order never matters.
Does it show steps?
Yes — six traced steps plus a breakdown table mirror every number on this page.
Can I print or share results?
Use the share bar to copy a link or results, download CSV/JSON, or print the worksheet.
Is my data stored?
No — calculations run locally; history stays in your browser only.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Union
In either set.
Intersection
In both sets.
Complement
In U but not A.
Cardinality
Element count.
Venn diagram
Overlapping-circle regions.

Authoritative References

Trusted sources and standards referenced by this calculator.

Applicable Standards

Common Core HSS-CP: sets and Venn diagrams

Diagrams & Illustrations

Visual intuition for every core idea. Select a card to enlarge it.

Did You Know?

Short intuition builders — great for class warm-ups.

Venn is 1880

John Venn drew overlapping circles for syllogisms.

∅ is universal subset

Empty set sits inside every set.

De Morgan dualizes

NOT flips AND to OR and back.

Compare Side by Side

Three disjoint regions tile the union — sum equals |union|.

RegionPartCountNote
Only A0leftA-only
Both0overlapshared
Only B0rightB-only

Recent Calculations

Your last runs on this page — stored only in this browser, never uploaded.

  1. Set Intersection Calculator: {3, 4}

    Current inputs — live

Study Plan

A week-by-week path from prerequisites to mastery. Your checklist progress saves in this browser.

Prerequisites

  • ▸Listing elements
  • ▸Reading Venn diagrams
  • ▸Even/odd multiples

Mastery progress — 0%

  • I dedupe automatically
  • I fix U first
  • I read neither
  1. 1

    Week 1 · ~15 min/day

    Operate on sets

    Goals

    • Union without dupes
    • Intersect correctly
    • Complement against U

    Practice

    Five roster ops daily.

Exam tips

  • •List regions
  • •Check counts sum

Practice Problems

0/3 solved

Try each problem first, peek at the hint only if stuck, then reveal the solution and mark it solved.

1
Opseasy

A = {1,2,3,4}, B = {3,4,5,6}. Union?

2
Opseasy

Same sets: intersection?

3
Lawsmedium

State De Morgan for union.

Printable Worksheet

Generate a fresh problem set for class or homework. Print it, or copy the answer key separately.

Problems Name
Arithmetic practice — set #1Name: __________ · Date: __________
  1. 1.18 × 47 =
  2. 2.8 ÷ 11 =
  3. 3.38 × 26 =
  4. 4.35 ÷ 4 =
  5. 5.21 − 16 =
  6. 6.2 + 26 =
  7. 7.14 ÷ 12 =
  8. 8.23 ÷ 3 =
  9. 9.49 ÷ 7 =
  10. 10.22 − 17 =
  11. 11.41 + 18 =
  12. 12.47 − 35 =

Formula Cheat Sheet

Every formula on this page in one printable table.

FormulaMeaningExample
A ∪ B: in eitherUnion{1,2} ∪ {2,3} = {1,2,3}
A ∩ B: in bothIntersection{1,2} ∩ {2,3} = {2}
(A ∪ B)′ = A′ ∩ B′De MorganDualize under NOT
Tip: every interactive block on this page — checklist, practice, worksheet, history — works offline and saves progress in your browser.

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Page Information

Last Updated:

2026-09-29

Version:

3.1.0-math

References:
License:

Free to use for educational and professional purposes.