Arithmetic math brain teasers are a fun way to challenge and improve your math skills. These brain teasers help exercise your mind and improve your math skills. These types of problems use basic mathematical operations such as addition, subtraction, multiplication, and division to challenge your problem-solving abilities. They can be a fun and engaging way to improve your math skills and boost your brainpower.

Here are some arithmetic brain teasers for you to try. You and your friends can put your heads together and solve these intriguing arithmetic problems on topics like equations, algebra, series and number operations, etc.

**Missing Numbers**

In this puzzle, your task is to figure out what numbers should replace the missing ones based on the patterns present in the series. Pay close attention to the sequence of numbers and any hints that may be provided. Dive in and see how many missing numbers you can uncover!

**Puzzle 1**

In the following figure, what will the two missing numbers be?

24 21 3

66 63 9

80 66 11

? ? 10

**Answer:** Missing numbers are 70 and 73.

**Solution:** Looking at the number in the third column, we can develop the following relationship:

- 3 × 7 = 21 + 3 = 24
- 9 × 7 = 63 + 3 = 66
- 11 × 7 = 77 + 3 = 80
- 10 × 7 = 70 + 3 = 73

**Number Series**

Number series puzzles are a great way to exercise your logical thinking skills and improve your ability to recognize patterns. A hint to solve this puzzle is to look for the number pattern in the given series.

**Puzzle 2**

Mohit writes a number series:

**1 2 3 4 1 2 3 4 1 …**

What is the sum of the first 99 terms of this series?

**Answer:** 246

**Solution:** Let’s write down the series: 1 2 3 4 1 2 3 4 1 2 3 4 ….

The first 4 terms repeat over and over. Therefore, the series can be grouped together with each group containing the 4 repeating terms.

(1 2 3 4) (1 2 3 4) (1 2 3 4) (1 2 3 4) (1 2 3 4) (1 2 3 4) ….

Divide 99 by 4, and you will get 24 such groups and 3 as a remainder.

The sum of the first four terms taken 24 times = (1+ 2 + 3 + 4) × 24 = 10 × 24 = 240

The sum of the remaining 3 terms = 1 + 2 + 3 = 6

Therefore, the total sum is 240 + 6 = 246

**Arithmetic Problems**

Arithmetic puzzles come in many forms, from simple calculations to complex problems. They can involve addition, subtraction, multiplication, division, fractions, and percentages. Some puzzles of these puzzles may require you to think outside the box or use creative thinking to arrive at a solution

**Puzzle 3**

Nidhi is 5 years old, her mother is 29 years old, and her grandmother is 54 years old.

In how many years will the sum of their ages be equal to 100 years?

**Hint:** A period of a year adds three years to the sum.

**Answer:** 4 years.

**Solution:** Currently, the sum of the ages of Nidhi, her mother, and her grandmother is 5 + 29 + 54 = 88 years.

Every year, this sum will increase by 3 (since each person’s age increases by 1).

After 1 year, the sum will be: 88 + 3 = 91

After 2 years, the sum will be: 88 + 3 + 3 = 94

After 3 years, the sum will be: 88 + 3 + 3 + 3 = 97

After 4 years, the sum will be: 88 + 3 + 3 + 3 + 3 = 100

Therefore, after 4 years, the sum of their ages will be 100.

**Puzzle 4**

Divide the clock face shown below into six regions so that the sum of the numbers in each region is the same:

**Hint:** What is the sum of all the numbers on the clock?

**Answer:**

**Solution:** The sum of all the numbers on the clock = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 = 78. We need to divide 78 into 6 regions which means the sum of the numbers in each region must be 78/6 = 13 — which is the same number we get below.

The solution to this problem is based on the following observation:

- 12 + 1 = 13
- 11 + 2 = 13
- 10 + 3 = 13
- 9 + 4 = 13
- 8 + 5 = 13
- 7 + 6 = 13

**Puzzle 5**

A stationery shop has notebooks in two colours: Red and Blue. The total cost of five red and six blue notebooks is ₹335. the cost of a blue notebook is ₹10 more than that of a red notebook. What is the price of a red notebook?

**Answer:** Rs 35

**Solution:** We want to find the price of a red notebook. Let’s say that it is Rs x

Then, the price of the blue notebook is Rs (x + 10).

The cost of five red and six blue notebooks is Rs 335. This gives:

5x + 6(x + 10) = 335;

5x + 6x + 60 = 335;

11x = 335 – 60 = 275;

x = 275/11 = 25;

So, the price of a red notebook = Rs 25

Price of blue notebook = Rs (x + 10) = Rs (25 + 10) = Rs 35.

Solving these puzzles must have been fun with those hints to help you set your thinking caps in the right direction. You will find that solving brain teasers is a revision of your schoolwork, as you must have recalled and used simple mathematical concepts you have learned in school while solving these brain teasers.