This page explains that combining two quantities and counting or measuring the combined quantity is addition in first principles. Addition is also explained using number-line.

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There are `3` red cars and `4` blue cars in the figure. What is the total number of cars in the figure?

- `7`
- `7`
- `3` or `4`

The answer is '`7`'

Considering the figure with `3` red cars and `4` blue cars. `3` and `4` are combined together and the counting is done from `1` to `7`. The resulting count is `7`.

A red pencil is `3` centimeters in length. A green pencil is `4` centimeters in length. What is the combined length of the pencils?

- `7`
- `7`
- `3` or `4`

The answer is '`7`'

The length of the red pencil is `3` centimeters. The length of the green pencil is `4` centimeters. The two pencils are placed side-by-side. The length measurements is taken from `0` and the measure at the end is `7`. The combined length is `7` centimeters.

The count or measure of quantities can be combined or *added*.

The *addition* results in count or measure of the combined quantity.

What is the sum of `3` and `4`? addition in number line

- `7`
- `7`
- `3` or `4`

The answer is '`7`'. Addition `3+4` is given in number-line. The count is started from `3`.

`4` jumps are made to land in `7`.

The result of the addition is `7`.

Which of the following is a meaning for the word "addition"?

- combining two quantities and measuring or counting the combined quantity
- combining two quantities and measuring or counting the combined quantity
- advertisement for specific audition

The answer is "combining two quantities and measuring or counting the combined quantity".

What is the term used to refer "combining two quantities and measuring / counting the combined quantity"?

- Pronunciation : Say the answer once

Spelling: Write the answer once

The answer is "addition".

**Addition - First Principles** : Two numbers are considered, each of which represents a count or measurement. The quantities represented by the numbers are combined to form a result representing a combined count or measurement. The combined count or measurement is the result of addition.

eg: `20` and `13` are combined together `20+13 = 33`.

`20` is an addend

`13` is also an addend

`33` is the sum

Which of the following is a meaning for the word "addend"?

- a number that is added to
- a number that is being added
- both the above
- both the above

The answer is "both the above".

What is the term used to refer "the numbers that are being added"?

- Pronunciation : Say the answer once

Spelling: Write the answer once

The answer is "addend".

Which of the following is a meaning for the word "sum"?

- an unspecified amount or number of
- the result of addition
- the result of addition

The answer is "the result of addition".

What is the term used to refer "the result of addition"?

- Pronunciation : Say the answer once

Spelling: Write the answer once

The answer is "sum".

*Solved Exercise Problem: *

What is the sum of `4` and `2`?

- `7`
- `6`
- `6`

The answer is '`6`'.

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