Numerical Expressions

Numerical Expressions

by Mary Winterhalder

​5.OA.2

​I can write, explain, and evaluate numerical expressions involving the four operations to solve up to two step word problems.

​Regina has 3 bags of marbles. There are 25 marbles in each bag. She wants to put an equal number of marbles into 5 bags. Which expression would show how many marbles can go in each bag?

​Regina has 3 bags of marbles. There are 25 marbles in each bag. She wants to put an equal number of marbles into 5 bags. Which expression would show how many marbles can go in each bag?

​What is this asking us to do with the 3 and 25?

​

​Explain.

​Regina has 3 bags of marbles. There are 25 marbles in each bag. She wants to put an equal number of marbles into 5 bags. Which expression would show how many marbles can go in each bag?

​What is this asking us to do with the 5?

​

​Explain.

Multiple Choice

Regina has 3 bags of marbles. There are 25 marbles in each bag. She wants to put an equal number of marbles into 5 bags. Which expression would show how many marbles can go in each bag?

• $$3\times25\times5$$  

• $$3\times\left(25\div5\right)$$  

• $$\left(3\times25\right)\div5$$  

• $$\left(3+25\right)\div5$$  

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

​These expressions have the same three numbers with the same operations. Let's see how the parenthesis changes what the answer will be.

​With the first expression there are no parenthesis and no exponents. So we look at multiplication and division.

​

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

​With the first expression there are no parenthesis and no exponents. So we look at multiplication and division.

​is our division part of the expression. So we will start there.

​

​Solve this part.

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

Now that we have solved the first part we can rewrite what we have left:

Now we just have to add.

​

​Solve this part.

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

Now we will look at the second expression.

​This one does have parenthesis.

​We will start there:

​Solve this part.

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

Still looking at the second expression.

​We have solved the parenthesis.

​Next we divide.

​Solve this part.

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

Compare the two expressions.

​Parenthesis

​Exponents

​Multiply or Divide (Left --> right)

​Add or Subtract (Left --> right)

​Take a moment to think through this. Then I will put up this same question for you to choose the correct answer for.

Multiple Choice

$$16-2\times3+4\div2$$  

• 23

• 7

• 12

• 8

​Hopefully you enjoyed this!