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Category: Mental Math

Ohtani’s Batting Average Sep 2024

  • khoitsma
  • Kids (middle school and up), Mathematics, Mental Math
  • 0 Comments

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What is the Day of the Week? Jan 2024

  • khoitsma
  • General, Kids (middle school and up), Mathematics, Mental Math
  • 0 Comments


odd months

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Engineering Math Nov 2023

  • khoitsma
  • Engineering, Kids (middle school and up), Mathematics, Mental Math
  • 0 Comments

“Often while working, an arithmetical answer is needed — exact is sometimes required, approximate is often acceptable — maybe the basis of a decision or a path forward is based on a few quick calculations, with more rigorous calculations to follow

Multiply by 11 (or 12). Just write down the answer !
Pascal’s Triangle
Aliquot Parts

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Rechnen, Multiplizieren und Addieren Nov 2022

  • khoitsma
  • Kids (middle school and up), Mathematics, Mental Math
  • 0 Comments

Sum the numbers — let me count the ways

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On Average Jun 2022

  • khoitsma
  • Kids (middle school and up), Mathematics, Mental Math
  • 0 Comments

Most everyone in math knows these tricks — here’s a summary of techniques used to make quick mental calculations of averages.

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Long Division — Just Write the Answer Oct 2021

  • khoitsma
  • Kids (middle school and up), Mental Math, Wolfram Alpha
  • 0 Comments

I found an exciting article recently; it describes the calculating powers of Professor Craig Aitken.

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