#### Need Help?

Get in touch with us  # Model With Math

## Key Concepts

• Model problems using equations, drawings and arrays

## Equation

First, find the equation of an array and add them row-wise or column-wise.

Example:

Write the equation for the given array.

Solution:

Here, there are 2 rows and 3 columns.

So, the row-wise equation of the image is 3 + 3 = 6.

There are 6 pumpkins present in the image.

### Drawing

Draw the image of the array and solve the problem.

Example:

Rachel ate 3 slices of pizza each day. Write how many slices of pizza she ate at the end of 3rd day. Draw the array and find the answer.

Solution:

She ate 3 slices of pizza on day 1.

On the 2nd day, she ate 3 slices of pizza.

On the 3rd day, she ate 3 slices of pizza.

So, at the end of the 3rd day, she ate 3 + 3 + 3 = 9 slices of pizza.

Therefore, Rachel ate 9 slices of pizza in total.

Example:

Hal arranged the leaves into 3 rows and 3 columns. How many leaves does Hal have in all?

Solution:

Here, there are 3 rows and 3 columns.

So, the equation of the image is 3 + 3 + 3 = 9.

There are 9 leaves present in the image.

Example:

Mindy draws 5 rows of stars in her notebook. In each row, she placed 5 columns of stars. So, how many stars does she draws?

Solution:

Here, there are 5 rows and 5 columns.

So, the equation of the image is 5 + 5 + 5 + 5 + 5 = 25.

There are 25 stars present in the image.

Example:

Nill has a collection of sunglasses. He placed those in 3 rows and 3 columns. So, how many sunglasses does he have in total?

Solution:

Here, there are 3 rows and 3 columns.

So, the equation of the image is, 3 + 3 + 3 = 9.

## Exercise

1. 2 rows of apples. 3 apples in each row. How many apples?
2. 2 rows of cars. 4 cars per row. How many cars?
3. Write two equations which explain the array.
• Write the equation by rows for the array.
• Write the equation by columns for the array.
• Jolene puts cakes out on the table. She puts 3 rows of cakes with 4 in each row on the table. How many cakes does she have in all?
• Write two equations which explains the array.
• Write the equation by columns for the array.
• Write two equations which explains the array.
• Larry puts cupcakes on a plate. He puts 2 rows of cupcakes with 5 in each row. How many cupcakes does

### What we have learned

• How to solve problems by using equations, drawings and arrays?

#### Related topics #### Addition and Multiplication Using Counters & Bar-Diagrams

Introduction: We can find the solution to the word problem by solving it. Here, in this topic, we can use 3 methods to find the solution. 1. Add using counters 2. Use factors to get the product 3. Write equations to find the unknown. Addition Equation: 8+8+8 =? Multiplication equation: 3×8=? Example 1: Andrew has […] #### Dilation: Definitions, Characteristics, and Similarities

Understanding Dilation A dilation is a transformation that produces an image that is of the same shape and different sizes. Dilation that creates a larger image is called enlargement. Describing Dilation Dilation of Scale Factor 2 The following figure undergoes a dilation with a scale factor of 2 giving an image A’ (2, 4), B’ […] #### How to Write and Interpret Numerical Expressions?

Write numerical expressions What is the Meaning of Numerical Expression? A numerical expression is a combination of numbers and integers using basic operations such as addition, subtraction, multiplication, or division. The word PEMDAS stands for: P → Parentheses E → Exponents M → Multiplication D → Division  A → Addition S → Subtraction         Some examples […]   