• About
  • Contact
  • Cookie
  • Disclaimer
  • Privacy Policy
  • Change the purpose of use

Tnhelearning.edu.vn - Various useful general information portal

  • Photo
  • Bio
  • How To
  • Tech

How to Calculate Numerical Thinking (Mind Math)

January 26, 2024 by admin Category: How To

You are viewing the article How to Calculate Numerical Thinking (Mind Math)  at Tnhelearning.edu.vn you can quickly access the necessary information in the table of contents of the article below.

X

wikiHow is a “wiki” site, which means that many of the articles here are written by multiple authors. To create this article, 20 people, some of whom are anonymous, have edited and improved the article over time.

This article has been viewed 9,694 times.

Numerical thinking or mental math is the ability to use applied algebra, mathematical methods, intelligence, and creativity to solve problems. All details about some of these methods are described in links to other wikiHow articles.

Prerequisite : Know how to memorize basic addition, subtraction, multiplication, and division.

Table of Contents

  • Steps
    • Addition and subtraction
    • Multiplication
  • Sources

Steps

Addition and subtraction

Image titled Do Number Sense (Mental Math) Step 1

Image titled Do Number Sense (Mental Math) Step 1

{“smallUrl”:”https://www.wikihow.com/images_en/thumb/7/73/Do-Number-Sense-%28Mental-Math%29-Step-1-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-1-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/7/73/Do- Number-Sense-%28Mental-Math%29-Step-1-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-1-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
Convert difficult additions to easy additions.

  • Rounds (added) numbers up to the next highest tens.
  • Public with other numbers.
  • Subtract the rounded total.
    • For example 88 + 56 = ? ; Rounds 88 to 90.

      Add 90 plus 56 = 146

      Subtract the number two that is added to 88 (to round to 90).

      146 – 2 = 144 ; that’s the answer!

    • The process is simply rearranging the problem 56 + (90 -2). Some examples of other uses of this method are: 99 = (100 – 1); 68 = (70 – 2)
    • You can also use this rearrangement method for subtraction.
  • Image titled Do Number Sense (Mental Math) Step 2

    Image titled Do Number Sense (Mental Math) Step 2

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/0/00/Do-Number-Sense-%28Mental-Math%29-Step-2-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-2-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/0/00/Do- Number-Sense-%28Mental-Math%29-Step-2-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-2-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Convert addition to multiplication. Multiplication is adding multiple occurrences of the same number.

    READ More:   How to Access another computer on the same network on a PC or Mac
  • Notice how many added numbers are repeated.
    • For example:

      7 + 25 + 7 +7 +7 =

      will be 25 + (4 × 7) =

      25 + 28 = 53

  • Image titled Do Number Sense (Mental Math) Step 3

    Image titled Do Number Sense (Mental Math) Step 3

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/e/e0/Do-Number-Sense-%28Mental-Math%29-Step-3-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-3-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/e/e0/Do- Number-Sense-%28Mental-Math%29-Step-3-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-3-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Add the inverse operation (Additive Opposites). The inverse addition can be +7 – 7. The inverse addition can also be 5 – 2 + 4 – 7.

  • Find some numbers that add or subtract to total 0. Use the example above: (NOTE: The image above is wrong. It shows 5 + 9 = 9 <–> -2 -7 = 9 which in when it should be 5 + 4 = 9 <–> -2 -7 = -9)

    5 + 4 = 9 is the addition and reverse of -2 -7 = -9

    Since they are additive inverses, the actual addition for all four numbers is not necessary; the answer is 0 (zero) after quitting.

    • Try this calculation:

      4 + 5 – 7 + 8 – 3 + 6 – 9 + 2 =

      will become:

      ( 4 + 5 ) – 9 + ( -7 – 3 ) + ( 8 + 2 ) + 6 = By grouping
      and remember, don’t add them; just remove the inverse addition from the problem.

      0 + 0 + 6 = 6

  • Multiplication

    Image titled Do Number Sense (Mental Math) Step 4

    Image titled Do Number Sense (Mental Math) Step 4

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/9/91/Do-Number-Sense-%28Mental-Math%29-Step-4-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-4-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/9/91/Do- Number-Sense-%28Mental-Math%29-Step-4-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-4-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Controls a few numbers ending in zero (zero). Example 120 × 120 =

  • Count the total of 0s at the end. (In this case, 2 zeros).
  • Multiply the remaining numbers in the problem.

    12 × 12 = 144

  • Add zeros that are counted at the end of the number;

    14400

  • Image titled Do Number Sense (Mental Math) Step 5

    Image titled Do Number Sense (Mental Math) Step 5

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/4/4e/Do-Number-Sense-%28Mental-Math%29-Step-5-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-5-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/4/4e/Do- Number-Sense-%28Mental-Math%29-Step-5-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-5-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Use the distributive property of multiplication to convert the hard multiplier to the easy multiplier. You can then use some of the methods below.

    • For example:

      Instead of taking 14 × 6

      divide 14 into 10 and 4, and multiply both by 6, then add them together…

      14 × 6 = = 6 ×(10 + 4) = (10 × 6) + (4 × 6) = 60 + 24 = 84.

    • For example:

      Instead of taking: 35 * 37 = ?

      do it this way: 35 × (35 + 2) =

      = 35 2 + (2 × 35) = 1225 + 70 = 1295

    READ More:   How to Treat Ankle Sprains
    Image titled Do Number Sense (Mental Math) Step 6

    Image titled Do Number Sense (Mental Math) Step 6

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/4/40/Do-Number-Sense-%28Mental-Math%29-Step-6-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-6-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/4/40/Do- Number-Sense-%28Mental-Math%29-Step-6-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-6-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Square numbers ending in 5 (five).

    Apply; 35 2 = ?

  • Ignoring the 5 at the end, multiply (3) by the next highest number (4).

    3 × 4 = 12

  • Write the number 25 at the end of the number.

    1225

  • Image titled Do Number Sense (Mental Math) Step 7

    Image titled Do Number Sense (Mental Math) Step 7

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/f/f8/Do-Number-Sense-%28Mental-Math%29-Step-7-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-7-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/f/f8/Do- Number-Sense-%28Mental-Math%29-Step-7-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-7-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Square some numbers with less than one or more squares that you already know.

    Apply 41 2 = ? and 39 2 = ?

  • Calculate the squared number you already know.

    40 2 = 1600

  • Decide whether you need to add or subtract. You will add the larger square and subtract the smaller number.
  • Add the first number that is squared with the next number that is squared.

    40 + 41 = 81

    40 + 39 = 79.

  • Add or subtract.

    1600 + 81 = 1.681 —> 41 2 = 1.681
    1600 – 79 = 1.521 —-> 39 2 = 1.521

    • This method is only suitable for some numbers with one unit above or below the original number.
    Image titled Do Number Sense (Mental Math) Step 8

    Image titled Do Number Sense (Mental Math) Step 8

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/8/87/Do-Number-Sense-%28Mental-Math%29-Step-8-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-8-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/8/87/Do- Number-Sense-%28Mental-Math%29-Step-8-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-8-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Simplify multiplication by using “Difference Squared”. Apply 39 × 51 = ?

  • Find the number that is equidistant from both numbers.

    In this case, the number 45 is the number that is 6 digits away from both numbers.

  • Square that number.

    45 2 = 2025

  • Square the number of distances from the number in the center.

    6 2 = 36

  • Subtract that number from the first number.

    2025 – 36 = 1989

    • If you are studying algebra, the formula is expressed as follows:

      51 × 39 =
      (45 + 6)×(45 – 6) = 45 2 -6 2
      ( x + y )×( x – y ) = x 2 – y 2

  • Image titled Do Number Sense (Mental Math) Step 9

    Image titled Do Number Sense (Mental Math) Step 9

    {“smallUrl”:”https://www.wikihow.com/images_en/thumb/4/4d/Do-Number-Sense-%28Mental-Math%29-Step-9-Version-3.jpg/v4-728px -Do-Number-Sense-%28Mental-Math%29-Step-9-Version-3.jpg”,”bigUrl”:”https://www.wikihow.com/images/thumb/4/4d/Do- Number-Sense-%28Mental-Math%29-Step-9-Version-3.jpg/v4-728px-Do-Number-Sense-%28Mental-Math%29-Step-9-Version-3.jpg”,” smallWidth”:460,”smallHeight”:345,”bigWidth”:728,”bigHeight”:546,”licensing”:”<div class=”mw-parser-output”></div>”}
    Multiply by 25. Apply 25 × 12 = ?

    READ More:   How to Heat Eyelash Clips
  • Multiply by 100 by adding two zeros to the end of the number (not 25).

    25 × 12
    1200

  • Divide by 4.

    1200 4 = 300
    25 × 12 = 300

  • Sources

    Calculator’s Cunning: The Art of Quick Reckoning by Karl Menninger

    X

    wikiHow is a “wiki” site, which means that many of the articles here are written by multiple authors. To create this article, 20 people, some of whom are anonymous, have edited and improved the article over time.

    This article has been viewed 9,694 times.

    Numerical thinking or mental math is the ability to use applied algebra, mathematical methods, intelligence, and creativity to solve problems. All details about some of these methods are described in links to other wikiHow articles.

    Prerequisite : Know how to memorize basic addition, subtraction, multiplication, and division.

    Thank you for reading this post How to Calculate Numerical Thinking (Mind Math) at Tnhelearning.edu.vn You can comment, see more related articles below and hope to help you with interesting information.

    Related Search:

    Related Posts

    How to Create Curved Text in Photoshop
    How to fall asleep faster
    How to Install FBReader to Read eBooks

    Category: How To

    Previous Post: « What is a calico cat? Why is a calico cat always female?
    Next Post: What is coconut worm? Where to buy, how much? How to prepare coconut weevils »

    Copyright © 2025 · Tnhelearning.edu.vn - Useful Knowledge