Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we will explore multiplication. Can anyone tell me what multiplication really is?
Isn't it just adding a number several times?
Exactly! Multiplication can be thought of as repeated addition. For example, 4 times 3 means adding 4 three times, which gives us 12. Any other examples?
Like 5 times 2 is the same as 5 + 5?
Very good! And we can write it as 5 × 2. Remember, 'multiplication' is a faster way of saying 'addition repeated.'
Now let’s discuss the properties of multiplication. Who knows a property of multiplication?
There's something called the commutative property, right?
That's correct! The commutative property states that a × b = b × a. Can anyone give me an example?
If I take 2 × 3, I can also say that’s 3 × 2, both equal 6!
Exactly! And we also have the associative property which means that grouping doesn't matter. Such as (2 × 3) × 4 = 2 × (3 × 4).
Multiplication is everywhere in our daily lives! For example, if oranges cost $2 each, how much for 4 oranges?
That would be 2 × 4, which is $8.
Great! Let's try a real-world example together. If one pizza costs $10, what's the cost for 3 pizzas?
It’s 10 × 3, so $30!
Fantastic! Multiplication helps you budget and understand pricing.
The operation of repeated addition.
Order does not affect the product.
Grouping does not affect the product.
Multiplying a number distributes over addition.
The number 1 does not change the value of a number when multiplied.
Multiplication is like adding more, 5 times 3 is 5, 5, 5, that's for sure!
Once upon a time, in a land of numbers, a group of 3 friends would join hands and 4 times every day, they would gather to celebrate by adding 3 over and over, until they realized they could simply multiply their gatherings!
To remember properties of multiplication, think of C.A.D.I. - Commutative, Associative, Distributive, Identity.
For multiplication, use the acronym 'CADI' to recall that it's Commutative, Associative, Distributive, and has an Identity element.
Term
What is multiplication?
Click to flip
Term
What is the commutative property?
Click to flip
Term
What is the associative property?
Click to flip
An arithmetic operation that represents repeated addition of the same number.
A property stating that changing the order of the numbers in multiplication does not change the product.
A property that states that the way in which numbers are grouped in multiplication does not affect the product.
A property that shows multiplication distributed over addition, expressed as a × (b + c) = a × b + a × c.
The number 1 in multiplication, as any number multiplied by 1 remains unchanged.
A property that ensures the product of any two real numbers is also a real number.
This section explains the concept of multiplication as repeated addition and introduces its properties and significance in mathematics.
In this section, multiplication is presented as a foundational arithmetic operation representing repeated addition. The section covers important properties of multiplication including the closure, commutative, associative, and distributive properties, and emphasizes the significance of multiplication in both academic concepts and real-life applications.
Multiplication is one of the fundamental operations in pure arithmetic, defined as repeated addition of the same number. For example, multiplying 2 by 3 (2 × 3) can be understood as adding 2 three times (2 + 2 + 2), leading to a result of 6. This manipulation highlights the connection between multiplication and addition, which is crucial for understanding broader mathematical concepts.
Understanding multiplication is essential as it lays the groundwork for advanced topics such as algebra and calculus, as well as everyday applications such as calculating area, rates, and finances.