Arithmetic operators in Go - Step-by-Step Execution

Concept Flow - Arithmetic operators

Start

↓

Initialize variables

↓

Apply operator: +, -, *, /, %

↓

Store result

↓

Use or print result

↓

End

This flow shows how arithmetic operators take values, perform calculations, and produce results step-by-step.

Execution Sample

Go

package main
import "fmt"
func main() {
  a, b := 10, 3
  result := a + b
  fmt.Println(result)
  result = a - b
  fmt.Println(result)
  result = a * b
  fmt.Println(result)
  result = a / b
  fmt.Println(result)
  result = a % b
  fmt.Println(result)
}

This Go program calculates and prints the sum, difference, product, quotient, and remainder of two numbers.

Execution Table

Step	Operation	Operands	Result	Explanation
1	Addition	10 + 3	13	Adds 10 and 3 to get 13
2	Subtraction	10 - 3	7	Subtracts 3 from 10 to get 7
3	Multiplication	10 * 3	30	Multiplies 10 by 3 to get 30
4	Division	10 / 3	3	Divides 10 by 3, integer division truncates to 3
5	Modulo	10 % 3	1	Remainder of 10 divided by 3 is 1
6	End	-	-	All operations done, program ends

💡 All arithmetic operations completed, program terminates.

Variable Tracker

Variable	Start	After Addition	After Subtraction	After Multiplication	After Division	After Modulo	Final
a	10	10	10	10	10	10	10
b	3	3	3	3	3	3	3
result	-	13	7	30	3	1	1

Key Moments - 2 Insights

Why does division 10 / 3 result in 3 and not 3.333?

In Go, dividing two integers uses integer division, which drops the decimal part. See execution_table step 4 where 10 / 3 equals 3.

What does the modulo operator (%) do?

Modulo gives the remainder after division. In step 5, 10 % 3 equals 1 because 3 goes into 10 three times with 1 left over.

Visual Quiz - 3 Questions

Look at the execution table, what is the result of the multiplication at step 3?

A 13

B 30

C 7

D 3

💡 Hint

Check the 'Result' column in execution_table row for step 3.

At which step does the program calculate the remainder of 10 divided by 3?

A Step 4

B Step 2

C Step 5

D Step 1

💡 Hint

Look for the modulo operation (%) in the 'Operation' column of execution_table.

If variable b was changed to 5, what would be the result of the subtraction at step 2?

A 5

B 7

C 3

D 15

💡 Hint

Subtraction is a - b; changing b to 5 means 10 - 5.

Concept Snapshot

Arithmetic operators in Go:
Use + for addition, - for subtraction,
* for multiplication, / for integer division,
% for remainder (modulo).
Integer division drops decimals.
Example: 10 / 3 = 3, 10 % 3 = 1.

Full Transcript

This visual execution shows how Go uses arithmetic operators to calculate with integers. We start with variables a=10 and b=3. Each step applies one operator: addition, subtraction, multiplication, division, and modulo. Division truncates decimals because both operands are integers. Modulo returns the remainder after division. The variable tracker shows how the result changes after each operation. Key moments clarify why division truncates and what modulo means. The quiz tests understanding of results and effects of changing variables.

Practice

1. Which arithmetic operator in Go is used to find the remainder of a division?

easy

A. /

B. +

C. *

D. %

Solution

1. Step 1: Understand the remainder operation

   The remainder operator returns what is left after division.

2. Step 2: Identify the correct operator in Go

   In Go, the remainder operator is represented by the percent sign '%'.

3. Final Answer:

   % -> Option D

4. Quick Check:

   Remainder = % [OK]

Hint: Remainder uses % like in many languages [OK]

Common Mistakes:

• Confusing division / with remainder %
• Using * for remainder
• Using + for remainder

2. Which of the following is the correct way to write a multiplication operation in Go?

easy

A. a x b

B. a . b

C. a * b

D. a & b

Solution

1. Step 1: Recall Go's multiplication syntax

   Go uses the asterisk '*' symbol for multiplication.

2. Step 2: Check each option

   Only 'a * b' uses the correct multiplication operator.

3. Final Answer:

   a * b -> Option C

4. Quick Check:

   Multiplication = * [OK]

Hint: Use * for multiplication, not x or & [OK]

Common Mistakes:

• Using 'x' instead of '*'
• Using '.' or '&' for multiplication
• Confusing syntax with other languages

3. What is the output of this Go code?

package main
import "fmt"
func main() {
  a := 7
  b := 3
  fmt.Println(a / b)
}

medium

A. 2.3333333

B. 2

C. 3

D. 0

Solution

1. Step 1: Identify variable types and operation

   Both a and b are integers, so division is integer division.

2. Step 2: Calculate integer division result

   7 divided by 3 is 2.333..., but integer division drops decimals, so result is 2.

3. Final Answer:

   2 -> Option B

4. Quick Check:

   Integer division 7/3 = 2 [OK]

Hint: Integer division drops decimals, result is int [OK]

Common Mistakes:

• Expecting float result
• Confusing integer division with float division
• Using wrong operator

4. Find the error in this Go code snippet:

package main
import "fmt"
func main() {
  x := 10
  y := 0
  fmt.Println(x / y)
}

medium

A. Division by zero causes runtime panic

B. Syntax error: missing semicolon

C. Variable y is not declared

D. No error, prints 0

Solution

1. Step 1: Analyze the division operation

   The code divides x by y, where y is zero.

2. Step 2: Understand Go's behavior on division by zero

   Dividing by zero causes a runtime panic (error) in Go.

3. Final Answer:

   Division by zero causes runtime panic -> Option A

4. Quick Check:

   Division by zero = runtime panic [OK]

Hint: Never divide by zero; it crashes the program [OK]

Common Mistakes:

• Thinking it prints 0
• Expecting compile-time error
• Ignoring runtime panic

5. Given the Go code below, what is the output?

package main
import "fmt"
func main() {
  a := 15
  b := 4
  c := a % b
  d := a / b
  fmt.Println(c + d)
}

hard

A. 6

B. 3

C. 19

D. 4

Solution

1. Step 1: Calculate remainder c = a % b

   15 % 4 equals 3 because 4*3=12 and 15-12=3.

2. Step 2: Calculate integer division d = a / b

   15 / 4 equals 3 because integer division drops decimals.

3. Step 3: Add c + d

   3 + 3 equals 6.

4. Final Answer:

   6 -> Option A

5. Quick Check:

   15 % 4 = 3, 15 / 4 = 3, 3 + 3 = 6 [OK]

Hint: Add remainder and integer division results carefully [OK]

Common Mistakes:

• Miscomputing remainder
• Using float division instead of integer
• Adding wrong values