
Using Arrays to Multiply Bigger Numbers
Karen Neal & Michelle Blaylock
4th grade
Gilbert Elementary School
Walker County Schools
Task

Overview
In this task, students will demonstrate how to multiply twodigit numbers using arrays. Students will be given a multiplication problem with a twodigit number by a twodigit number. They will use graph paper to solve the problem by breaking it down into partial products (smaller arrays to find the answer).
Illustrative Task
Multiplication with Base Ten Blocks
Model each expression with a drawing of base 10 blocks. Show how you use the model to find the product.
2 * 13 11 * 4 5(15) (13)(6) Multiplying Bigger Numbers(Using Arrays)
There are 16 kids in our class. Each kid brings in 12 colored pencils for the empty class pencil drawer. How many pencils does our class have now?
 Solve and show your work using what you already know about arrays.
 Create your own multiplication story using two 2 digit numbers.
 Solve and show your work!


GPS Addressed

M4N3. Students will solve problems involving multiplication of 23 digit numbers by 12 digit numbers.


Video Information


Use these questions to guide your thinking about some of the important teacher ideas in the lesson featured in the video clip.
 What kinds of questions does the teacher ask to promote students’ problem solving?
 How is the teacher gauging students’ current understandings and building from those understandings?
 Consider the GPS standards listed with this video.
 What makes this lesson different from lessons you have taught on this topic?


