In this Grade 4 lesson from Pengi Math Chapter 4, students learn to multiply two-digit numbers by two-digit numbers using area models and partial products. They explore patterns with multiples of 10, organize four partial products in a 2x2 area model, and combine them to build toward the standard algorithm. The lesson also applies these multiplication strategies to real-world problems.
Section 1
Visualizing 2-by-2 Multiplication with an Area Model
To multiply two two-digit numbers, we can decompose each number into tens and ones and use the distributive property.
This can be visualized with an area model, where the total area is the sum of four smaller areas, known as partial products.
For factors and :
Section 2
Grouping Partial Products from an Area Model
The four partial products from an area model can be grouped to form two partial products. This grouping combines the products related to the ones digit and the products related to the tens digit of one of the factors. For a problem like :
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter
Expand to review the lesson summary and core properties.
Section 1
Visualizing 2-by-2 Multiplication with an Area Model
To multiply two two-digit numbers, we can decompose each number into tens and ones and use the distributive property.
This can be visualized with an area model, where the total area is the sum of four smaller areas, known as partial products.
For factors and :
Section 2
Grouping Partial Products from an Area Model
The four partial products from an area model can be grouped to form two partial products. This grouping combines the products related to the ones digit and the products related to the tens digit of one of the factors. For a problem like :
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter