Big Ideas:
To find an unknown product of two larger numbers, we can use what we know about place value and known multiplication facts to compute partial products that can be combined to form the total product.
Using the area model allows students to see that they are not simply multiplying digits but rather multiplying values. By using expanded notation, students will make sense of the value each digit represents in a multiplication problem. This task requires students to build on their knowledge of area acquired in 4th grade and connect it to multiplication of multi-digit whole numbers. This lays the foundation for mastery of multi-digit whole numbers using the standard algorithm.
Vocabulary:
standard form, expanded form, distributive property, area model, product, partial products
Special Materials:
Grid paper (optional)
Lesson plan