MULTIPLICATION
Unit 3: Multi-Digit Operation and Measurement
Multiply by 1 digit Numbers
Multiply by two 2 digit Numbers
In fourth grade, students learn how to multiply up to four-digit numbers times a one-digit number with both the Area Model, and the Standard Algorithm.
Students learn that multiplication is the operation that finds the total of equal groups of items.
They also learn that the two numbers you are multiplying together are called the factors, and the answer to the multiplication problem is called the product.
For example: Factor X Factor = Product, so in the equation 5 X 6 = 30, 5 and 6 are the factors and 30 is the product.
We teach students to use their place value knowledge to learn how multiply. Therefor, prior to teaching students how to multiply with the standard algorithm, we teach them how to multiply with the area model.
In fourth grade, students also learn how to multiply two two-digit numbers with both the Area Model, and the Standard Algorithm.
Area Model
Standard Algorithm
Standard Algorithm
Students also learn how to check to see if their multiplication answers are reasonable, using Estimation.
To estimate with multiplication, you round the multi-digit number and multiply it by the single-digit number, or you round both multi-digit numbers and multiply them together. Then, you check with the actual answer to see if your answer is reasonable.
Use Multiplication to Convert Measurements
There is a land called Gallon.
In the land of Gallon, there are 4 queens.
Each queen has 2 ponies.
Each pony has 2 carrots.
1 gallon = 4 quarts
1 gallon = 8 pints
1 gallon = 16 cups
1 quart = 2 pints
1 quart = 4 cups
1 pint = 2 cups
Find Perimeter and Area
Students will be able to use the perimeter formula for rectangles
for example: for a rectangle with the length of 12 feet and the width of 5 feet: P = (2 x 12) + (2 x 5)
Students will be able to use the area formula for rectangles,
for example: for a rectangle with the length of 9 feet and a width of 3 feet. A = 9 x 3