What if the 2 numbers were switched? How can you even go below zero?

Below zero there would be negative numbers

Can you take away 1/2 of something?

Depends on the item. For example, you can cut a sandwich in half and take one piece.

How far does negative numbers go? Is it like normal numbers? Never ending?

Yes, Negative numbers go on forever just on the other side of the number line.

Why subtraction has this (-) sign?

It is easier to use the (-) sign is stead of saying plus a negative.

How would you represent negative numbers?

Negative numbers represent the distance in the opposite direction on the number line. The negative symbol can be seen as a subtraction sign, because 0 - 5= -5.

who invented subtraction?

Nobody knows but it was found in a book called Mercantile Arithmetic by Robert Recorde

how do I make adding easier

you can write it all down on a piece of paper.

What person invented math

No one person invented math, many people contributed to it's development over many, many years.

Main content

Class 1 math (India)

Unit 1: Lesson 6

What is subtraction?

Intro to subtraction

Name: Intro to subtraction
Uploaded: 2014-04-25T19:24:36Z
Description: Sal talks about what it means to subtract. The examples he uses are 4-3 and 5-2.

Google Classroom

Sal talks about what it means to subtract. The examples he uses are 4-3 and 5-2. Created by Sal Khan.

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[Au]^79
Posted 9 years ago. Direct link to [Au]^79's post “What if the 2 numbers wer...”
What if the 2 numbers were switched? How can you even go below zero?
(52 votes)
Answer
- Blueberry
  Posted 3 years ago. Direct link to Blueberry's post “Below zero there would be...”
  Below zero there would be negative numbers
  (2 votes)
imange77
Posted 5 years ago. Direct link to imange77's post “How far does negative num...”
How far does negative numbers go? Is it like normal numbers? Never ending?
(17 votes)
Answer
- Devajsurya
  Posted 5 years ago. Direct link to Devajsurya's post “Yes, Negative numbers go...”
  Yes, Negative numbers go on forever just on the other side of the number line.
  (14 votes)
Hisha Harb
Posted 5 years ago. Direct link to Hisha Harb's post “Why subtraction has this ...”
Why subtraction has this (-) sign?
(10 votes)
Answer
- Michael Bedsaul
  Posted 5 years ago. Direct link to Michael Bedsaul's post “It is easier to use the (...”
  It is easier to use the (-) sign is stead of saying plus a negative.
  (5 votes)
Dean Howell
Posted 5 years ago. Direct link to Dean Howell's post “Can you take away 1/2 of ...”
Can you take away 1/2 of something?
(19 votes)
Answer
- pixiehex
  Posted 5 years ago. Direct link to pixiehex's post “Depends on the item. For ...”
  Depends on the item. For example, you can cut a sandwich in half and take one piece.
  (2 votes)
sunshineT3
Posted 5 years ago. Direct link to sunshineT3's post “So then it's possible to ...”
So then it's possible to do negative addition?
(14 votes)
Answer
- Edwin Li
  Posted 4 years ago. Direct link to Edwin Li's post “It is possible, because y...”
  It is possible, because you can add a number to a negative number to make it positive or closer to 0.
  (1 vote)
🤗😇Corby😇🤗
Posted 6 years ago. Direct link to 🤗😇Corby😇🤗's post “who invented subtraction?”
who invented subtraction?
(8 votes)
Answer
- Krish Dulal
  Posted 6 years ago. Direct link to Krish Dulal's post “Nobody knows but it was f...”
  Nobody knows but it was found in a book called Mercantile Arithmetic by Robert Recorde
  (16 votes)
NumerousSeven
Posted 5 years ago. Direct link to NumerousSeven's post “How would you represent n...”
How would you represent negative numbers?
(10 votes)
Answer
- Deirdre Moore
  Posted 5 years ago. Direct link to Deirdre Moore's post “Negative numbers represen...”
  Negative numbers represent the distance in the opposite direction on the number line. The negative symbol can be seen as a subtraction sign, because 0 - 5= -5.
  (6 votes)
🤗😇Corby😇🤗
Posted 6 years ago. Direct link to 🤗😇Corby😇🤗's post “What person invented math”
What person invented math
(6 votes)
Answer
- FunkyChicken
  Posted 6 years ago. Direct link to FunkyChicken's post “No one person invented ma...”
  No one person invented math, many people contributed to it's development over many, many years.
  (16 votes)
patrick parr
Posted 4 years ago. Direct link to patrick parr's post “how do i learn how to do ...”
how do i learn how to do more easy subtraction cuz i suck at subtraton and im super good at addition.
(9 votes)
Answer
htimeaus
Posted 6 years ago. Direct link to htimeaus's post “how do I make adding easi...”
how do I make adding easier
(8 votes)
Answer
- EmersonS
  Posted 9 months ago. Direct link to EmersonS's post “you can write it all down...”
  you can write it all down on a piece of paper.
  (2 votes)

Video transcript

Voiceover:Let's explore what it means to subtract numbers. So let's say that I want to figure out what 4, what 4 minus 3 is. 4 minus 3. So one way to think about this, is you start with 4 objects. And so let me just draw 4 objects. So there I have 1, 2, 3, and 4. And when I ... So this is the 4 objects right over here. And when I say minus 3, or if I'm going to subtract 3 from the 4, one way to think about it is, I'm going to take 3 of these 4 objects away. So let's do that. So I'm going to take away 1, I'm going to take away 2, and I'm going to take away 3. Notice, I took away 1, 2, 3 objects. So how many do I have leftover? Well, if I start with 4 and I take away 3, I subtract 3, 4 minus 3, I am left with, I am left with, 1 object, right over here. So 4 minus 3 is equal to, is equal to 1. Fascinating. Let's do another one of these. Let's figure out what 5, what 5, what 5 minus 2 is. And let's write it this way. Let's say we want to figure out something, some question mark, some question mark ... Actually, let me just clear this out. I'll just do it right over here, actually. So let's say we have some question mark. So there's some unknown number right over here. So I'll just put a question mark over here. And we say that unknown number is equal to, is equal to 5, 5 minus 2. Minus 2. Minus 2. So what is this going to be? Well let's visualize it. This means I have 5 things and I'm going to take away 2 of them and this is going to be what I have leftover after I start with 5 and take away 2. So I have 1, 2, 3, 4, 5 things. Now I am going to take away 2 of them. So I'm going to take away 1 and 2. So I took away 1, 2 objects. So how many do I have leftover? Well, I have leftover these, these ... Let me do this in a different color. I have leftover these purple things right over here. So how many is that? How many do I have leftover? Well, I have leftover 1, 2, 3 of my original 5. So something is equal is 5 minus 2. That something is 3. 3 is equal to 5 minus 2. Let me just replace this with a 3. So we see that 3 ... Actually, let me do the 3 in the same color as this green. So we see that 3, 3 is equal to 5 minus 2 or we could say that 5 minus 2 is equal to 3. Either way.

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