# Missing Operations Worksheets

This is one of those topics that are like a preamble to algebra skills. I guess that is why they call it prealgebra? The goal here is to look at fixed equations that are missing operators (such as +, -, x) and determine which of those operators are missing. Once these operators placed in the right spot, the math statement becomes true. You can determine what is missing by solving the equations and counterbalancing any other operators that may be present. This selection of worksheets and lessons help students recognize missing addition and subtraction operators.

### Aligned Standard: 1.OA.B.4

- Addition or Subtraction Step-by-Step Lesson- Find which of the two signs are missing and drop it in there.
- Guided Lesson - See if you can get the gold medal. The first two make it possible.
- Guided Lesson Explanation - I give you a one sentence explanation here for the problems, but make sure to read the introduction, it will make more sense.
- Practice Worksheet - I definitely got a bit happy with the 5s and 7s.
- Matching Worksheet - Match the partial and whole problems together.

- Answer Keys - These are for all the unlocked materials above.

### Guided Lessons

It is funny for as many emails I get for having cute pictures with the worksheets, I get as many emails with people against them. What do you think?

- Guided Lesson 1 - Here is where we lose a few students; horizontal operations with an integer in the teens.
- Guided Lesson 2 - We set them on a course for success here.
- Step-by-Step Lesson 1 - See if you can out fox this one.
- Step-by-Step Lesson 2 - More of the same here.
- Step-by-Step Lesson 3 - If students are having a really hard time with this skill, give them this one.

### Practice Worksheets

These are designed to be more drill oriented.

- Independent Practice Worksheet 1- I stuck with the horizontal format to be more a challenge for them.
- Independent Practice Worksheet 2- Just another dose of problems for you.
- Matching Worksheet - You can complete this without understanding the symbol, but it is a nice way to ease into the skill.
- True/False Worksheet - These are black and white; right or wrong.

### Finding Missing Operations in an Equation

Ever found yourself in a situation where you have to determine a missing operation in an equation? Well, like finding the missing terms in a sequence, there are cases where you have to determine the missing operation in an equation. So, how do you find a missing operation? You do not have to freak out as it is very easy. Here is an example that will help you grasp the concept!

Example: Solve 72( ? ) 27 - 322 ÷ 14 = 1,921

Now, there are many different approaches to solving mathematical equations. A tip that will help you reach your answer is a quick and easy way is to take a reverse approach. You know that there are pairs of math operations that counter one another. Addition and subtraction operations counter one another and so does multiplication and division. Remember that when you are working with equations you can apply any math operations you wish, as long as you apply it to both sides of the equal symbol. So, if a fixed number is being subtracted from something, you can counter that side by adding that value to both sides of the equals sign.

By looking at this equation, we know that we must divide 322 by 14, as per the order of operations.

72 ( ? ) 27 - 23 = 1,921

To further solve this, you need to add 23 to both sides of the equation;

72 ( ? ) 27 - 23 + 23 = 1,921 + 23. 72 ( ? ) 27=1,944

The final step is more of a trial-and-error method, and it is where you will have to use your common sense. The four basic arithmetic operations that you can use here include addition, subtraction, multiplication, and division. It is obvious that subtracting 27 from 72 will never give such a big number; also, adding these numbers will give a very small answer. The division operation will give a small number, and when you apply the multiplication operation, you will get 1944.

72 × 27 = 1,944