In this Grade 4 Eureka Math lesson, students learn to multiply two-digit by two-digit numbers by applying the distributive property to generate four partial products using an area model. Students break each factor into tens and ones, then find and sum the four smaller products — ones times ones, ones times tens, tens times ones, and tens times tens — to find the total. This lesson builds directly on prior work with multiples of 10 and prepares students for efficient two-digit multiplication strategies.
Section 1
Representing Multiplication with an Array
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 array, where the total area is the sum of four smaller areas, known as partial products.
For factors and :
Section 2
Recording Partial Products Vertically
To find the total product, the four partial products are recorded vertically, aligned by place value, and then added together.
Expand to review the lesson summary and core properties.
Section 1
Representing Multiplication with an Array
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 array, where the total area is the sum of four smaller areas, known as partial products.
For factors and :
Section 2
Recording Partial Products Vertically
To find the total product, the four partial products are recorded vertically, aligned by place value, and then added together.