Colorful House of Math logo
Magnifying glass closely exploring planet EarthExplore
  • Purple dashboard icon represented as a browser window

    Dashboard

  • Purple math kettlebell and gray dummbell

    Bootcamps

  • Purple bank vault with round, golden door

    Math Vault

  • Black graduate's cap with a purple tassel

    Math Essentials

  • Bespectacled math expert wearing a purple tie

    Mentor-on-Demand

  • Encyclopedia volume with math symbols on pages

    Encyclopedia

  • Laptop and desklamp on purple desk with books and calculator

    Digital Tools

  • Purple plus sign with video game controls on it

    Games

  • Yellow math study tips lightbulb

    Study Tips

Sign upLog in
Colorful House of Math logo
Sign upLog in
Dashboard
Bootcamps
Math Vault
Mentor-on-Demand
Math Essentials
Encyclopedia
Digital Tools
Games
Study Tips

Settings
Exit preview
Language: English
Language: English
Numbers and Quantities iconNumbers and Quantities
Algebra iconAlgebra
Geometry iconGeometry
Statistics and Probability iconStatistics and Probability
Functions iconFunctions
Proofs iconProofs
Encyclopedia>Numbers and Quantities>Arithmetic>Mental Arithmetic

Mental Arithmetic

Numbers and Quantities iconNumbers and Quantities
Numbers
Arithmetic
Addition and SubtractionMultiplicationDivisionPowers and RootsCalculation OrderSignsMental Arithmetic
Fractions and Percentages
Quantities
Economy
Vectors
Algebra iconAlgebra
Geometry iconGeometry
Statistics and Probability iconStatistics and Probability
Functions iconFunctions
Proofs iconProofs
  • How to Do Mental Math (Rounding)

    numbersAndQuantitiesIcon
    Article on How to Do Mental Math (Rounding)
    Read here
  • How to Do Mental Math (Estimates)

    numbersAndQuantitiesIcon
    Article on How to Do Mental Math (Estimates)
    Read here
  • How to Round a Number

    numbersAndQuantitiesIcon
    Article on How to Round a Number
    Read here
  • How to Make Estimates (Mental Math)

    numbersAndQuantitiesIcon
    Article on How to Make Estimates (Mental Math)
    Read here
  • How to Calculate the Cost per Unit

    numbersAndQuantitiesIcon
    Article on How to Calculate the Cost per Unit
    Read here
    Magnifying glass exploring planet Earth
    Explore
    Purple dashboard icon represented as a browser window
    Dashboard
    Magnifying glass for search function
    Search
    Purple speech balloon chat icon
    Chat
    About Us
    • About House of Math
    • The Employees
    • Career
    • Media
    • Lectures
    Contact
    • post@houseofmath.com
    • + 47 22 150 300
    • Munkedamsveien 45C, 0250 Oslo Norge
    Links
      WeTakeAction
    • Tutoring
    • Encyclopedia
    • Bootcamps
    • Math Essentials
    • Math Vault

    logo
    TermsPrivacyCookies