Multiplication strategies

In this lesson, we will learn:

• Understanding multiplication using arrays
• Representing a product as either: (1) a smaller product and a sum, or (2) a bigger product and a difference
• Tips and tricks for memorizing the 9 × multiplication table facts

Notes:

• Multiplication is just repeated addition

• Multiplication facts can be shown in an array model with circles/dots
• Using the array model, it shows that multiplication facts can be broken into groups of smaller multiplication facts:

• Using the same array model, we can find the next multiplication fact by adding another row:

• Therefore, a product can be found as a smaller product and a sum

• Or, it could be found as a bigger product and a difference

• The 9 × multiplication tables can be memorized using your fingers!
• Notice that the first ten multiples of 9 are mirrored after the 5-digit in 45
• Ex. 9, 18, 27, 36, 45 $\parallel$ 54, 63, 72, 81, 90