The reason I ask this question "What multiplication fact can be found by using the arrays for 2x9 and 5x9 ?" because I want to understand what exactly it mean, Then I could help my son to do the homework.

This is not my son post it to ask you.
Thanks.

This site should help you.

http://www.haelmedia.com/OnlineActivities_txh/mc_txh3_002.html

No worries! I'm here to help clarify the meaning of the question and guide you on how to find the answer.

In the question, it asks for the multiplication fact that can be found using arrays for 2x9 and 5x9. Let's break it down:

1. Arrays: Arrays represent a way to organize objects in rows and columns to visually understand multiplication. In this case, we will use arrays to represent the numbers 2x9 and 5x9.

2. 2x9: This means multiplying the number 2 by 9.

3. 5x9: This means multiplying the number 5 by 9.

Now, to find the multiplication fact, we'll multiply the two numbers together.

For 2x9:
You can use the array method by drawing 2 rows and 9 columns. Count the total number of objects in the array, and that will give you the answer.

For 5x9:
Again, use the array method by drawing 5 rows and 9 columns. Count the total number of objects in the array to find the answer.

Once you have the total number of objects for both arrays, you will have found the multiplication facts for 2x9 and 5x9.

So, to summarize, to find the multiplication facts using the arrays for 2x9 and 5x9, you'll need to draw arrays, count the total number of objects, and that will give you the answers.