Multiplication

Ms. Allen’s 3rd Grade Math Class

What is multiplication?● The basic idea of multiplication is repeated

addition.

For example: 5 × 3 = 5 + 5 + 5 = 15

● But as well as multiplying by whole numbers, you can

also multiply by fractions or decimals.

For example 5 × 3½ = 5 + 5 + 5 + (half of 5) = 17.5

Source: http://www.mathsisfun.com/definitions/multiplication.html

Why do we need multiplication?

● Multiplication is everywhere!

● It’s the basis of math, you can’t learn math without learning you’re basics!

● It is a necessary life skill. You’ll use it everyday.○ At your future job○ While shopping○ And many other places!

Different methods we will practice while learning multiplication

We will master multiplication in 3 ways. You will learn about...

● Multiplication Times Table● Multiplication Word Problems● Lattice Algorithm

Multiplication Times Table

This is a tool that we will be able to use. I want you to be able to figure out the problem first before you go to this chart. Think of it as a way to double check your work.

To learn more on these tables go to: http://www.mathsisfun.com/tables.html

Multiplication TableThis is a simple multiplication table and is meant to help you. Always try the problem first and look back at this table to help.

-4X3=? You should get 12 by either adding 3 four times or adding 4 three times. When using the chart it doesn’t matter what number you start with on the chart. 4X3 is the same as 3X4.

-Click to see a demonstration on the chart

Try These:

Without looking at the chart try these few problems. After you think you have the answer you may go back and check the table. Remember to trace the numbers along the horizontal and the vertical bars to find your answer.

- 4x3 -2x5 -8x2

Multiplication Word Problems

This is the most common way that we will learn multiplication. Not only does it increase your multiplication skills but your reading skills as well. These problems will be kept simple.

Remember, multiplication is just repeated addition.

Let’s try a problem:

Mike and his two friend’s went trick or treating. They each have 6 pieces of candy. How much candy do they all have together?

We write down each friend. Then give them each six pieces of candy. Now we count how many candies all the friends have together. This is 6X3 but in written form using repeated addition.

Mike C,C,C,C,C,CFriend 1 C,C,C,C,C,CFriend 2 C,C,C,C,C,C

TOTAL: 18 pieces

To learn more on word problems and get some fun practice go to: https://www.khanacademy.org/math/arithmetic/multiplication-division/mult-div-word-problems/e/arithmetic_word_problems

Lattice Algorithm

This algorithm is meant to be used when multiplying larger digits. Its important that you understand the concept of multiplication before mastering this algorithm.

With this method you will be drawing, adding, and multiplying.

Watch this video to understand: http://www.youtube.com/watch?v=VoXJA-9WzNI

Credits: (Website Help)● http://www.mathsisfun.com/definitions/multiplication.html

● http://www.mathsisfun.com/tables.html

● https://www.khanacademy.org/math/arithmetic/multiplication-division/mult-div-word-problems/e/arithmetic_word_problems

● http://www.youtube.com/watch?v=VoXJA-9WzNI