So 1 + 4 is equal to 4 + 1 in 0:45. Is this the commutative law?

Yes, very good observation. It is also called the Commutative Property of Addition.

so 1+4=5 and 4+1=5 3+2=5 2+3=5

Correct. There are infinite ways to make five though, so I wouldn't attempt to try all of them. :P

when your doing this you can have it in different numbers and it can equal the same amount

Yes! you can use different answers and get the sam amount.

why cant subtraction be backwards?

you can subtract a negative number too , it same thing plu the absolute value of that negative number , you will learn that in grade 5 .

why does it make me watch them 2 times

So you can make sure you understand everything.

How do you add or subtract negative numbers

Type "add and subtracting negative numbers" in the search box at the top of the page and you'll get a bunch of answers that are guaranteed to satisfy your needs.

Main content

Kindergarten

Course: Kindergarten > Unit 2

Lesson 4: Put together, take apart

Addition and subtraction within 10

Name: Addition and subtraction within 10
Uploaded: 2015-03-27T16:18:02Z
Description: Sal solves addition and subtraction problems with number 10 or less.

Google Classroom

Sal solves addition and subtraction problems with number 10 or less.

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Marvin Cohen
Posted 8 years ago. Direct link to Marvin Cohen's post “So 1 + 4 is equal to 4 + ...”
So 1 + 4 is equal to 4 + 1 in
0:45
. Is this the commutative law?
Button navigates to signup pageComment on Marvin Cohen's post “So 1 + 4 is equal to 4 + ...”
(19 votes)
Answer
- Wudaifu
  Posted 8 years ago. Direct link to Wudaifu's post “Yes, very good observatio...”
  Yes, very good observation. It is also called the Commutative Property of Addition.
  Comment on Wudaifu's post “Yes, very good observatio...”
  (29 votes)
Dean Howell
Posted 5 years ago. Direct link to Dean Howell's post “Commutative law, Commutat...”
Commutative law, Commutative Property of Addition... there is a certain thrill in learning proper names for common operations through comments in early math!
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(10 votes)
Answer
990009589
Posted 6 years ago. Direct link to 990009589's post “so 1+4=5 and 4+1=5 3+2=5...”
so 1+4=5 and 4+1=5 3+2=5 2+3=5
Button navigates to signup pageComment on 990009589's post “so 1+4=5 and 4+1=5 3+2=5...”
(5 votes)
Answer
- FunkyChicken
  Posted 6 years ago. Direct link to FunkyChicken's post “Correct. There are infini...”
  Correct. There are infinite ways to make five though, so I wouldn't attempt to try all of them. :P
  Comment on FunkyChicken's post “Correct. There are infini...”
  (2 votes)
evweb23
Posted 7 years ago. Direct link to evweb23's post “why does it make me watch...”
why does it make me watch them 2 times
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(1 vote)
Answer
- ShootTheGun
  Posted 7 years ago. Direct link to ShootTheGun's post “So you can make sure you ...”
  So you can make sure you understand everything.
  Button navigates to signup page
  (8 votes)
anastasiaserilavey
Posted 4 years ago. Direct link to anastasiaserilavey's post “why doesn't this make sen...”
why doesn't this make sense
Button navigates to signup pageComment on anastasiaserilavey's post “why doesn't this make sen...”
(3 votes)
Answer
Math boy (jaydez smithen)
Posted 6 years ago. Direct link to Math boy (jaydez smithen)'s post “when your doing this you ...”
when your doing this you can have it in different numbers and it can equal the same amount
Button navigates to signup pageComment on Math boy (jaydez smithen)'s post “when your doing this you ...”
(3 votes)
Answer
- Luna Hope Darkness
  Posted 6 years ago. Direct link to Luna Hope Darkness's post “Yes! you can use differen...”
  Yes! you can use different answers and get the sam amount.
  Button navigates to signup page
  (2 votes)
Mystic Starky 64ds
Posted 7 years ago. Direct link to Mystic Starky 64ds's post “Is it related addition an...”
Is it related addition and subtraction
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(3 votes)
Answer
- Alex L.
  Posted 7 years ago. Direct link to Alex L.'s post “Addition and subtraction ...”
  Addition and subtraction are related with the fact that adding and then subtracting the same number will give you 0. Basically one undos the other.
  Button navigates to signup page
  (1 vote)
Jeff
Posted 7 years ago. Direct link to Jeff's post “why cant subtraction be b...”
why cant subtraction be backwards?
Button navigates to signup pageComment on Jeff's post “why cant subtraction be b...”
(3 votes)
Answer
- jimmyjiang1123
  Posted 7 years ago. Direct link to jimmyjiang1123's post “you can subtract a negati...”
  you can subtract a negative number too , it same thing plu the absolute value of that negative number , you will learn that in grade 5 .
  Button navigates to signup page
  (3 votes)
allison.rodriquez
Posted 7 years ago. Direct link to allison.rodriquez's post “what is 32 multiplyed by ...”
what is 32 multiplyed by 90
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(2 votes)
Answer
- Unako
  Posted 7 years ago. Direct link to Unako's post “2880. 90X2 =180. 90X30=27...”
  2880. 90X2 =180. 90X30=2700. So 2700+180= 2880. You can shorten this by multiplying 9 by 2 and 3 respectively and adding the zeros as place holders. 9X2=18 (since it is really 90 you would add a zero to the answer). 9X3=27 (You would add one zero for the zero in the 90, and one zero for the zero in the 30) then add the two answers (with zeros) together. Hope this helps!
  Button navigates to signup page
  (1 vote)
~
Posted 8 years ago. Direct link to ~'s post “How do you add or subtrac...”
How do you add or subtract negative numbers
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(1 vote)
Answer
- Johnathan
  Posted 8 years ago. Direct link to Johnathan's post “Type "add and subtracting...”
  Type "add and subtracting negative numbers" in the search box at the top of the page and you'll get a bunch of answers that are guaranteed to satisfy your needs.
  Button navigates to signup page
  (2 votes)

Video transcript

- [Voiceover] So we're given four different equations here and each of them have a blank, and we need to fill in that blank with a missing number. So let's do each of these. So on the left hand side of this equation, we have one plus four, so one plus four is the same thing as... Well, one plus four is five. If we take four, and if you add one more, you're gonna have five. So now, we finished that one, because one plus four is the same thing as five. Now here, we're saying four plus something is the same thing as five. Well, we just figured out that one plus four, or four plus one is the same thing as five. So four plus one is five. So notice there, we have the equation, four plus one is the same thing as five. Equals means that what's on the left is the same thing as what you have on the right. Now we have blank plus two is equal to five. So what plus two is the same thing as five? Well, three plus two is equal to five, or five is equal to three plus two. Now you go here. Well now you have three plus blank is equal to five. Well, we already figured it out, because three plus two is equal to five. So we can write three plus two is equal to five, and then we can check ourselves. And then we can keep going. So now we have some subtraction. So what's the same thing as nine minus three? So if I have nine things, and if I were to take away three of them, I'm going to have six left. Nine minus three is the same thing as six. 10 minus blank is equal to six. So what do I have to take away from 10 in order to have six left over? Well, if I take four away from 10, I'm going to have six left over. Now something minus one is the same thing as six. Well, seven minus one is going to be equal to six. And then we get eight minus blank is equal to six. So how many do I have to take away from eight in order to get to six? Well, if I take away one, I'm going to get seven. If I take away two, I'm going to have six. So eight minus two is equal to six.