Arithmetic operators in R Programming - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the '+' operator do in R?

The '+' operator adds two numbers together. For example, 3 + 2 equals 5.

beginner

How do you subtract numbers in R?

Use the '-' operator to subtract one number from another. For example, 5 - 2 equals 3.

beginner

What is the symbol for multiplication in R?

The '*' symbol is used for multiplication. For example, 4 * 3 equals 12.

beginner

How do you divide numbers in R?

Use the '/' operator to divide one number by another. For example, 10 / 2 equals 5.

beginner

What does the '^' operator do in R?

The '^' operator raises a number to the power of another. For example, 2 ^ 3 equals 8 (2 multiplied by itself 3 times).

What is the result of 7 + 3 in R?

A 73

B 10

C 4

D 1

7 + 3 adds the two numbers to get 10.

Which operator is used for multiplication in R?

A *

B -

C /

D +

The '*' operator multiplies numbers.

What does 9 / 3 equal in R?

A 3

B 6

C 27

D 0

9 divided by 3 equals 3.

How do you write '2 to the power of 4' in R?

A 2 ^^ 4

B 2 ** 4

C 4 ^^ 2

D 2 ^ 4

The '^' operator is used for exponentiation in R.

What is the result of 5 - 8 in R?

A 13

B 3

C -3

D 0

5 minus 8 equals -3.

Explain how to perform basic arithmetic operations in R using operators.

Think about how you add, subtract, multiply, divide, and raise numbers to powers.

What operator would you use to multiply two numbers in R? Give an example.

Multiplication uses a symbol that looks like a star.

Practice

1. Which of the following operators in R is used for multiplication?

easy

A. -

B. +

C. *

D. /

Solution

1. Step 1: Recall basic arithmetic operators in R

   In R, * is used for multiplication, + for addition, - for subtraction, and / for division.

2. Step 2: Identify the multiplication operator

   The operator * multiplies two numbers.

3. Final Answer:

   * -> Option C

4. Quick Check:

   Multiplication operator = * [OK]

Hint: Remember * means multiply in math and R [OK]

Common Mistakes:

• Confusing * with + or -
• Using / for multiplication
• Using ^ for multiplication

2. Which of the following is the correct syntax to calculate the remainder of 10 divided by 3 in R?

easy

A. 10 %% 3

B. 10 /% 3

C. 10 %/% 3

D. 10 % 3

Solution

1. Step 1: Understand remainder operator in R

   In R, the operator %% gives the remainder after division.

2. Step 2: Identify correct syntax for remainder

   10 %% 3 calculates remainder of 10 divided by 3, which is 1.

3. Final Answer:

   10 %% 3 -> Option A

4. Quick Check:

   Remainder operator = %% [OK]

Hint: Use %% for remainder, not % or /% [OK]

Common Mistakes:

• Using single % instead of %%
• Confusing integer division %/% with remainder %%
• Typing operators incorrectly like /%

3. What is the output of the following R code?

result <- 5 + 3 * 2
print(result)

medium

A. 16

B. 11

C. 10

D. 13

Solution

1. Step 1: Apply operator precedence in R

   Multiplication (*) has higher priority than addition (+), so 3 * 2 = 6 is calculated first.

2. Step 2: Calculate the expression

   Then add 5 + 6 = 11.

3. Final Answer:

   11 -> Option B

4. Quick Check:

   5 + (3 * 2) = 11 [OK]

Hint: Multiply before adding due to operator precedence [OK]

Common Mistakes:

• Adding before multiplying
• Ignoring operator precedence
• Calculating 5 + 3 first

4. Identify the error in this R code snippet:

value <- 10 %/ 3
print(value)

medium

A. Syntax error due to incorrect operator

B. Runs correctly and prints 3

C. Runs correctly and prints 1

D. Runtime error due to division by zero

Solution

1. Step 1: Check the operator used

   The operator %/ is not valid in R. Integer division uses %/%.

2. Step 2: Identify the error type

   Using %/ causes a syntax error because R does not recognize it.

3. Final Answer:

   Syntax error due to incorrect operator -> Option A

4. Quick Check:

   Integer division operator is %/% not %/ [OK]

Hint: Use %/% for integer division, not %/ [OK]

Common Mistakes:

• Typing %/ instead of %/%
• Confusing remainder %% with integer division
• Expecting output despite syntax error

5. You want to calculate the integer division and remainder of 17 divided by 4 in R. Which code correctly assigns both results to variables int_div and rem?

hard

A. int_div <- 17 %/ 4rem <- 17 %% 4

B. int_div <- 17 %% 4rem <- 17 %/% 4

C. int_div <- 17 / 4rem <- 17 % 4

D. int_div <- 17 %/% 4rem <- 17 %% 4

Solution

1. Step 1: Recall operators for integer division and remainder

   Integer division uses %/% and remainder uses %% in R.

2. Step 2: Match operators to variables

   int_div <- 17 %/% 4 correctly assigns integer division result (4).
   rem <- 17 %% 4 correctly assigns remainder (1).

3. Final Answer:

   int_div <- 17 %/% 4; rem <- 17 %% 4 -> Option D

4. Quick Check:

   Integer division %/% and remainder %% used correctly [OK]

Hint: Use %/% for int division, %% for remainder [OK]

Common Mistakes:

• Swapping operators for int division and remainder
• Using invalid operator %/
• Using / instead of %/% for integer division