ISEE Lower Level Math : Operations

Study concepts, example questions & explanations for ISEE Lower Level Math

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Example Questions

Example Question #3 : How To Subtract

Solve the following number sentence.

Possible Answers:

None of the other answers.

Correct answer:

Explanation:

To successfully solve this question, the order of operations must be used.

There are 4 steps in the order of operations and they are as follows:

1. P - Solve all problems within a parentheses.

2. E - Solve any numbers that have an exponent.

3. MD - From the left side of the problem to the right side of the problem solve all Division and Multiplication.

4. AS - From the left side of the problem to the right side of the problem solve all Subtraction and Addition.

 Based on the rules the first part of the problem to be solved is  as it is in parentheses.  The other parts of the problem remain the same and are re-written until their step is reached.

Next the exponent is to be solved.  The exponent number in this problem is which means to multuply the base to itself  times.

Next looking from the left to the right of the problem there are no multiplication or division calculations to do so skip to the last step.

Finally, starting from the left side of the problem and moving to the right side of the problem each set of two numbers will be solved until the final answer is reached.  Starting with  then  and lastly .

The final answer would be .

Example Question #3 : How To Subtract

Sam is shipping five boxes, which weigh 50 pounds in total. The first four boxes weigh 8 pounds, 12 pounds, 9 pounds, and 15 pounds. How much does the last box weigh?

Possible Answers:

Correct answer:

Explanation:

First, add the first four boxes together:

Now, subtract this number from the total to find the weight of the remaining box:

Example Question #4 : How To Subtract

Evaluate:

Possible Answers:

Correct answer:

Explanation:

First, adding negative numbers is the same as subtracting them:

Now subtract:

Example Question #3 : How To Subtract

Mark went to the grocery store to buy ingredients to make a cake. He bought eggs for $2.99, flour for $4.99, sugar for $3.99, and butter for $2.50. If he paid the cashier with a $20 bill, how much money did he recieve in change?

Possible Answers:

Correct answer:

Explanation:

Since the question is asking how much money did Mark have left over, we need to subtract the cost of each item he bought from $20.

There are two ways of solving this problem:

  • We can add up the cost of all the ingredients and then subtract the total cost from $20.00

  • We can subtract the cost of each item from $20.00. Note, if we choose to solve the problem this way, we must follow order of operations and go from left to right     

Example Question #6 : How To Subtract

Solve:

Possible Answers:

 

Correct answer:

Explanation:

In order to solve this problem, you must follow order of operations. One way of remembering the correct order is to remember the acronym PEMDAS. PEMDAS reminds you what you need to do first.

  • P = Parentheses
  • E = Exponents
  • M = Multiplication
  • D = Division
  • A = Addition
  • S = Subtraction

Note: For Multiplication and Division, and Addition and Subtraction, you do whatever operation comes first from left to right. So, if subtraction comes before addition, you do the subtraction first.

In this question, you are asked to solve:  

First, we subtract  from since it is in the parenthesis (PEMDAS)

Second, we multiply by (PEMDAS)

Third, we subtract from . We subtract from  first because we have to go from left to right (PEMDAS)

Lastly, we subtract from to get the answer.

Example Question #16 : Money And Time

Sally bought 3 different picture frames and paid a total of $60. If the first frame cost $15 and the second frame cost $25, how much did the third frame cost?

Possible Answers:

Correct answer:

Explanation:

In order to find out how much the third frame costs, we need to subtract the cost of the first two frames ($15 and $25) from the total amount ($60).

There are two ways to subtract the cost of the first two frames from the total amount:

Method 1

We can subtract the total amount spent on the first two frames from $60

                                                      

Remember to follow Order of Operations (PEMDAS) and add the numbers in parenthesis first.

The cost of the third frame was $20

Method 2

We can subtract the cost of each frame from $60

The cost of the third frame was $20

Example Question #5 : How To Subtract

Which of the following numbers can complete the sequence below?

Possible Answers:

Correct answer:

Explanation:

In this sequence, each subsequent number is 3 less than the previous number. Given that 3 less than 20 is equal to 17, the correct answer is 17. 

Example Question #17 : Money And Time

Larry owes Jon $5.75. If Larry gives Jon a $10 bill and Jon gives him change in quarters, how many quarters does Jon give to Larry?

Possible Answers:

Correct answer:

Explanation:

If Larry gives Jon a $10 bill to pay him back for $5.75, Jon will need to give Larry back .

If Jon gives the change in quarters, he will give him  quarters.

 

 

Example Question #323 : Numbers And Operations

If Eliza buys a book for  dollars and then sells it for  dollars, how much profit does she make (in dollars)?

Possible Answers:

Correct answer:

Explanation:

If Eliza buys a book for  dollars and then sells it for  dollars, her profit will be equal to the selling price, minus the initial cost of the book. 

This results in . Therefore,  dollars is the correct answer. 

Example Question #11 : How To Subtract

What is the solution to the expression below?

Possible Answers:

Correct answer:

Explanation:

The first step to solve for  is to convert the fractions into a form in which they share a least common denominator. The least common denominator of  and  is . Therefore, the expression should be rewritten as:

This results in , the correct answer. 

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