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Adding decimals: 0.822+5.65

Sal solves 0.822+5.65 using "standard algorithm".  Created by Sal Khan.

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  • duskpin seedling style avatar for user raygunner
    hi
    can you divide the ten by the two hundred
    (0 votes)
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  • male robot hal style avatar for user Luis Febro
    When exactly the "standard algorithm" happens in this solution?
    (4 votes)
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    • duskpin ultimate style avatar for user Polina Vitić
      To use the standard algorithm, follow these steps in order:

      Line up the decimal points

         36.413
      12.5
      + 30.08
      ------------


      Fill in the blank spots with zeros

         36.413
      12.500
      + 30.080
      ------------


      Add, beginning with the smallest place first

      thousandths: 3+0+0=3
      hundredths: 1+0+8=9
      tenths: 4+5+0=9
      ones: 6+2+0=8
      tens: 3+1+3=7

      Be sure to drop the decimal down into the answer

         36.413
      12.500
      + 30.080
      ------------
      78.993


      Hope this helps!
      (2 votes)
  • leafers seed style avatar for user Nesha Strong
    Why do you put the smallest decimal on top and the longest decimal on the bottom?
    (0 votes)
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  • blobby green style avatar for user Alexis Whitaker
    Why do decimals seem so complicated all the time?
    (3 votes)
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  • leaf yellow style avatar for user me
    1️⃣Listen, there are 2 types of operations: Commutative and NOT commutative. WHAT DOES THAT MEAN? Here... Commutative: the operations that u can switch numbers in, and when you do so, they give you the same answer. These operations (+ and x) Addition and multiplication.🙌🏻 NOT commutative: the operations that you CAN'T switch between them, and if you do so, it would change the answer and these are the operations. (- and ÷) 🙌🏻 -⏩BY THE WAY, it's NOT wrong to do it the first way, it's just easier, since we have 4 digits and 3 digits, the better is to change to make the addition process easier, that's all!🌻⭐ 2.10+ 10.25// It's better to switch the digits just to make the addition easier. (✅IT'S NOT WRONG TO DO IT THIS WAY❌)👍🤓 It can be written as: 10.25+2.10 // this is called the commutative property.😊📜 10.25+2.10= 12.35 You might find it FASTER this way!😄🤝🏻 HOPE THAT HELPED YOU! #YouKhanLearnAnything!💪It doesn't matter which decimal value is longer or shorter to write, or which comes first or second… In the video Sal arranged the higher valued decimal on top, (he placed the value with 5-whole over the 0-whole), and says it is just his preference, and it would add the same either way. because… ★ Addition is Commutative, (able to be rearranged and still add the same). 2 + 5 = 7 5 + 2 = 7 ★We can have either decimal value on top or bottom, but… ★ We must LINE UP THE DECIMALS to keep each place value aligned throughout the calculation. 0.822 + 5.65 = ? 0.822 + 5.65 ———————— 6.472 ←same answer 5.65 + 0.822 ———————— 6.472 ←same answer ★Use the decimals to guide the place value alignment: line up the decimals above and below, then add each column of numbers, empty spaces are equal to zero. (ㆁωㆁ) Hope this helps someone!
    (2 votes)
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    • male robot johnny style avatar for user ¿Slimy?
      It doesn't matter which decimal value is longer or shorter to write, or which comes first or second…

      In the video Sal arranged the higher valued decimal on top, (he placed the value with 5-whole over the 0-whole), and says it is just his preference, and it would add the same either way.
      because…

      ★ Addition is Commutative, (able to be rearranged and still add the same).
      2 + 5 = 7
      5 + 2 = 7

      ★We can have either decimal value on top or bottom, but…

      ★ We must LINE UP THE DECIMALS to keep each place value aligned throughout the calculation.

      0.822 + 5.65 = ?

      0.822
      + 5.65
      ————————
      6.472 ←same answer


      5.65
      + 0.822
      ————————
      6.472 ←same answer

      ★Use the decimals to guide the place value alignment: line up the decimals above and below, then add each column of numbers, empty spaces are equal to zero.

      (ㆁωㆁ) Hope this helps someone!
      (3 votes)
  • piceratops ultimate style avatar for user firestorm168
    Is'nt the 0.822 suppose to go above the 5.65
    (2 votes)
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  • leafers sapling style avatar for user bellew.harley
    Do you have to wuch thes veteos
    (3 votes)
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  • blobby green style avatar for user kohner.mitchell
    do you like cheese
    (3 votes)
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  • leaf yellow style avatar for user me
    It doesn't matter which decimal value is longer or shorter to write, or which comes first or second…

    In the video Sal arranged the higher valued decimal on top, (he placed the value with 5-whole over the 0-whole), and says it is just his preference, and it would add the same either way.
    because…

    ★ Addition is Commutative, (able to be rearranged and still add the same).
    2 + 5 = 7
    5 + 2 = 7

    ★We can have either decimal value on top or bottom, but…

    ★ We must LINE UP THE DECIMALS to keep each place value aligned throughout the calculation.

    0.822 + 5.65 = ?

    0.822
    + 5.65
    ————————
    6.472 ←same answer


    5.65
    + 0.822
    ————————
    6.472 ←same answer

    ★Use the decimals to guide the place value alignment: line up the decimals above and below, then add each column of numbers, empty spaces are equal to zero.

    (ㆁωㆁ) Hope this helps someone!
    (2 votes)
    Default Khan Academy avatar avatar for user
  • aqualine tree style avatar for user brigette brandt: I loVe My MuMmY
    why do the assignments have due dates
    (1 vote)
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    • male robot johnny style avatar for user ¿Slimy?
      It doesn't matter which decimal value is longer or shorter to write, or which comes first or second…

      In the video Sal arranged the higher valued decimal on top, (he placed the value with 5-whole over the 0-whole), and says it is just his preference, and it would add the same either way.
      because…

      ★ Addition is Commutative, (able to be rearranged and still add the same).
      2 + 5 = 7
      5 + 2 = 7

      ★We can have either decimal value on top or bottom, but…

      ★ We must LINE UP THE DECIMALS to keep each place value aligned throughout the calculation.

      0.822 + 5.65 = ?

      0.822
      + 5.65
      ————————
      6.472 ←same answer


      5.65
      + 0.822
      ————————
      6.472 ←same answer

      ★Use the decimals to guide the place value alignment: line up the decimals above and below, then add each column of numbers, empty spaces are equal to zero.

      (ㆁωㆁ) Hope this helps someone!
      (4 votes)

Video transcript

We're asked to add 0.822 to 5.65. So let me rewrite this. And when I rewrite it, I want to line up the decimals so that we add the right place to the right place. And so we could write either number first, although I like to write the larger number first. So let's write 5.65. And remember, the important thing is that we line up the decimal points. So if we write 0.822-- so we line up the decimal. Let me line up the decimal first. So I'll write the decimal right below the other decimal. And it is 0.822. And now we are ready to add. So let's see what's going on here. So I like to start in the smallest place. That way, the carrying works out well. So you might say, wait, I need to add this 2 thousandths to something. I don't see anything up here. Well, you could say there's just a 0 thousandths right up here. Then it makes it very clear. Well, 0 thousandths plus 2 thousandths is going to be 2 thousandths. 5 hundredths plus 2 hundredths is 7 hundredths. 6 tenths plus 8 tenths is 14 tenths. Well, 14 tenths is the same thing as 4 tenths and 1 one. Another way of thinking about it is you're carrying the 1. But really, what you're saying is, look, this is 14 tenths. I could write it as 4 tenths and a 1, or a ones place, a 1 in a ones place. Then you have 1 plus 5 is 6. And of course, you cannot forget the decimal. The decimal goes right there. And this is 6.472.