## How to find the missing number in a subtraction

Contents

- How to find the missing number in a subtraction
- How to explain a sum?
- What are computational strategies?
- How to start a sum?
- Calculate sums
- What is addition and examples?
- What are missing numbers?
- What is an accounting calculation?
- Missing number in addition and subtraction
- What is the calculation of audit techniques?
- What are the mental arithmetic exercises like?
- When do children learn to add and subtract?
- Examples of summands for elementary school

This paper aims to address the concepts of Addition and Subtraction, adapted to Early Childhood Education; as we can see these will not be completed at this stage, since they are in the so-called preoperational period; preconceptual and intuitive.

Addition is a mathematical function associated with the union of disjoint sets. The result of this operation – sum or total – is the cardinality of the resulting set. It relates the parts to the whole: (4 + 2 = 6) synthesis; while renaming the whole according to its parts: (6 = 4 +2) analysis.

## How to explain a sum?

Addition is the mathematical operation that results from combining several quantities into one. The numbers that are added are called addends and the result is called sum or total. For its notation, the sign + is used between the addends, which is read as “plus”.

## What are computational strategies?

Mental arithmetic strategies consist of using number facts to solve more complex operations. Number facts are numerical relationships that we know by heart, they vary from person to person, but there are some popular ones that are shared by most of us.

## How to start a sum?

First we must place the addends one below the other, you can imagine vertical lines that form boxes. In the first box from right to left should be the ones, in the second the tens, in the third the hundreds and so on.

### Calculate sums

The brain uses a skill called working memory to record the steps needed to solve, for example, a mathematical problem; that way all the mathematical facts and numerical concepts we learn are stored in our long-term memory. For that reason, we can remember these steps, and even do them mentally almost automatically, whenever we want to make a calculation.

The player controls the movements of the character of the game “Kilometrus” to advance and overcome the obstacles that are presented to him, converting the distances from meters to centimeters. Likewise, it is necessary to perform addition and subtraction operations in order to estimate the distance to advance. The development of estimation and strategy skills is encouraged, as well as mental calculation.

Outside of school, in the real world, mental arithmetic also helps in the simplest processes, such as: calculating how much candy your allowance is enough for; knowing how much you have to pay at the supermarket; or how much money you have to give back in change.

### What is addition and examples?

Addition is one of the four basic operations of arithmetic that consists of the addition of two or more elements to arrive at a final result where everything is included. The addition symbol is the plus symbol (+) and is inserted between the elements to be added, for example: 2+3=5.

### What are missing numbers?

The numbers 4 8 15 16 16 23 42 are one of Lost’s recurring and most important themes. They first appeared in the first season episode “Numbers” as the winning numbers of the lottery that made Hurley a multi-millionaire.

### What is an accounting calculation?

Calculation, in mathematics, refers to the procedure, with established steps, by means of which, the result of an operation can be reached. … Calculus is applied in various professional fields, such as architecture, engineering, computer science, accounting, economics and finance.

### Missing number in addition and subtraction

We should use all of them frequently when proposing addition and subtraction exercises, so that our children and students will be familiar with them when the time comes to pose and solve mathematical problems written in words.

In order to understand the mathematical foundation of addition and subtraction with transformation, we need to keep in mind some features of the decimal number system (you can read the full post I wrote about it here)

For example: in 57, the position of the 7 is that of the units, it is worth 1 and, therefore, the 7 placed there is worth 7 units. On the other hand, the position of the 5 is that of the tens, it is worth 10 times that of the ones. In other words, the 5 placed there is worth 50 units. Its absolute value is 5 and its relative value is 50.

This is the real subtraction with transformation, only that it is a transformation from left to right (the opposite of how it is done in addition). Let’s look at a hand-drawn example to make it easier to understand. To subtract 56 – 19:

The disadvantage of this procedure is that there are operations where continuous “borrowing” is required and this can become confusing to the student if he forgets any. What can be done to avoid this is to ask the student to first do all the necessary transformations (borrowings) and then do all the subtractions. It may be necessary to cross out twice in the same position. In this way:

### What is the calculation of audit techniques?

This is the amount set by the auditor indicating possible material misstatements in the financial statements as a whole and in certain transactions, accounting balances or disclosures in the notes to the financial statements.

### What are the mental arithmetic exercises like?

Mental arithmetic requires the use of a set of skills that allow performing mathematical operations “in the head”, without using pencil and paper or a calculator. One such skill is remembering math facts such as 8 x 5 = 40. Other skills include rounding numbers and estimating.

### When do children learn to add and subtract?

At what age do you learn to add? At the age of 4 or 5, when the knowledge of numbers has already been acquired, children begin to learn the concept of addition and to do simple one-digit sums. It is also at this age, after addition, that children begin to subtract.

### Examples of summands for elementary school

Carmen Romero García does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Mathematical competence, understood as the application of mathematical concepts and procedures to solve problems in real contexts, is very important for the integral formation of students.

However, despite the recognized importance of this subject, it is often perceived by students as a difficult, abstract, boring and disconnected from reality. This leads to a lack of motivation among students, and makes mathematics one of the subjects with the highest failure rate.

When students are faced with mathematical tasks they may experience feelings of tension or fear of not being able to perform a task or failing. If this feeling persists over time, it generates mental block. This feeling of inordinate fear towards mathematics and problem solving has been defined as math anxiety and can trigger an attitude of task avoidance, which interferes with their learning.