Description
TenMarks teaches you how to use arrays to show multiplication.
Transcript
How to Use Arrays to Show Multiplication Using arrays to show multiplication In this problem, we need to find 2×4. We can use arrays to explore multiplication. We’re going to use the following steps to make an array. Before we do this though, let's talk about what an array is. An array is a group of objects arranged in rows and columns. Each row is filled and has the same number of objects. Each column is filled and has the same number of objects. To make an array, we start with our first step. We start making the array with the rows. We're going to use two counters to begin the rows, one for each row. Here, we have two rows and we got two rows from the two in our problem. We’re going to use four counters. Our second step is to use four counters in each row to show the columns because we had four in our problem. Here, we have our four counters in each row. We have four columns. Our third step is to count to find the total number of counters or the product of 2×4. Two is our equal rows, so we have two rows times four is the counters in each rows or our columns, so we have four counters in each row and when I count them, I get eight, the total number of counters, so 2×4=8. Let's make the connection between 2×4 and 4×2. To show 4×2, we’re going to make four rows of two counters. Here we have four rows with two counters in each row. We have four equal number of rows and we have two counters in each row and that equals eight, the total number of counters. 2×4 has the same product as 4×2 which is eight, so 2×4 has the same product as 4×2. This is called the commutative property of multiplication. The commutative property of multiplication states that when the order of factor is change, the product is still the same. Thing to keep in mind and remember is that you can make arrays to find the product of two numbers. You can use and make an array to find the product of two numbers. Remember that an array is a group of objects arranged in rows and columns. The commutative property of multiplication states that when the order of factor is changed, the product still is the same. For example, if we took 3×5 is equal 5×3 which is 15, so 3×5 is equal to 5×3 which is 15.
