Base 10 Model
Matrix Method
Standard Algorithm
Properties of Multiplication
Math Jokes
100
What are the names for each of these units?
Green shape: cube
Orange shape: flat
Blue shape: rod
Yellow shape: unit
100
What equation is being solved with this matrix? What mistake did the person make when setting up this matrix?
25 x 42 = ?
The person put the smaller number on the top and the larger number down the side.
100
Why does multiplication usually make a number larger?
Because you are combining equal groups of a number, which increases the total amount (when multiplying by numbers greater than 1).
100
What does the 3 represent in the following equation?
3 x 4 = 12
The 3, which is the first factor, is the multiplicand.
100
Why was six afraid of seven?
Because 7 8 9!
(7 ate 9)
200
How many units are in each of these shapes?
Cube: 1000 units
Flat: 100 units
Rod: 10 units
Unit: 1 unit
200
What should my matrix box look like for the following question?
79 x 6 = ?
200
Explain why we place a zero (placeholder) when multiplying the tens digit in the standard algorithm.
Because we are multiplying by a multiple of 10 (like 30, not 3). The zero shows we are multiplying in the tens place.
200
What does the 4 represent in the following equation?
3 x 4 = 12
The second factor, which is the 4, is the multiplier.
200
Why did the student wear glasses in math class?
To improve di-vision!
300
Looking at this base 10 model, how many rods should result from the multiplication of 1 rod x 1 rod?
1 group of 10 rods = 10 rods = 100 units
300
Use the matrix method to solve the following question:
67 x 43 = ?
2881
300
A student solved 46 × 32 and got 1,292.
Their work:
46 × 32 ------ 92 +120 ------ 1,292
What mistake did they make?
They forgot to add the zero placeholder when multiplying by 3 (which is actually 30).
Correct product: 1,472
300
What does the 12 in this equation represent?
3 x 4 = 12
The 12 is the product.
300
Why was the equal sign so humble?
Because it knew it wasn’t less than or greater than anyone else!
400
What is the math question represented by this Base 10 Model?
21 x 14 = _____
400
Use the matrix method to solve the following equation:
344 x 12 = ?
4128
400
Why does multiplying by 10, 100, or 1,000 change the position of digits in a number?
Because each place value increases by a factor of 10, so the digits shift left when multiplied by powers of 10.
400
What do the 3 and 4 represent?
3 x 4 = 12
The 3 and 4 are the factors.
400
Why did the two 4s skip lunch?
Because they already ATE!
(4 x 2 OR 4 + 4 is equal to 8)
500
Solve the following question using the Base 10 Model:
17 x 23 = ?
391
500
Solve the following question using the Matrix Multiplication Method:
365 x 231 = ?
365 x 231 = 84315
500
How is the standard algorithm similar to the Base 10 model?
Both break numbers apart by place value and multiply each part.
The standard algorithm just organizes the partial products in a compact vertical form.
500
Why does any number multiplied by 0 equal 0?
E.g., 4 x 0 = 0
If you have nothing (= 0) and 99 people give you nothing (= 0) that means you still have nothing.
When you are multiplying, you are saying that there is a group. If you have 0 groups of 4, you have nothing.
500
I am a two-digit number.
I am a two-digit number.
The product of my digits is 24.
The sum of my digits is 10.
When you multiply me by 9, the digits of the product add up to 9.
What number am I?
64
6 × 4 = 24
6 + 4 = 10
64 × 9 = 576 → 5 + 7 + 6 = 18 → 1 + 8 = 9
