Fun math puzzles

A great variety of fun math puzzles that will help you sharpen your basic math skills at the same time. Fun does not necessarily means easy.

Fun does not necessarily means easy. As a math major, anything that becomes challenging is fun for me. You may feel the same way if math is your thing.

I cannot guarantee all the puzzles will be fun, but I can guarantee that some of the puzzles will be very challenging.

Even though the skills that you need is basic math, some of these puzzles will require some reflection before you figure them out. Try to do the puzzles yourself before looking at the solution at the end of the page.

The puzzles on this page are warm ups. More complicated puzzles will be added on a regular basis. Let's get started with some fun math puzzles!

Fun math puzzles

Here is the solution to the fun math puzzles above

Puzzle #1:

Use four 5s and some of the symbols +, ×, −, and ÷ to give expressions for 0, 1, 2, and 5

Puzzle #2:

Use the two isosceles triangles below to make a star?

A pair of isosceles triangles


Puzzle #3:

It takes 1629 digits to number the pages of a book. How many pages does the book have?

Puzzle #4:

Use only 4 straight lines to cut a pizza into 11 pieces?

Puzzle #5:

Would you rather work for 30 days and get paid 5 millions dollars, or be paid 1 cent the first day, 2 cents the second day, 4 cents the third day, and so on...?

Puzzle #6:

Place 10 dishes along the 4 edges of a table so that each edge has the same amount of dishes

Puzzle #7:

There is an interesting two-digit number X. With a 9 before it, it is three times as large plus 3 as with a 9 after it. What is the number?

Puzzle #8:

In a family with 4 siblings, John is older than Mary, Peter is younger than John, Mary is older than Peter, and Sarah is older than John. Who is the second oldest in the family? Who is the youngest?

Puzzle #1 solution:

5 − 5 + 5 − 5 = 0

5 − 5 + 5 ÷ 5 = 1

5 ÷5 + 5 ÷ 5 = 1 + 1 = 2

5 × (5 − 5) + 5 = 5

Puzzle #2 solution:

Star made with 2 triangles


Puzzle #3:

From page #1 to page # 9, there are 9 pages

From page #10 to page # 99, there are 90 pages. However, since each page number has 2 digits, there are 180 digits from page # 10 to page # 99

From page #100 to page # 999, there are 900 pages. However, since each page number has 3 digits, there are 2700 digits from page # 100 to page # 999

Since there are 1629 digits, we know so far that number of pages is less than 900

Now, we need to find out how many digits there are for those pages greater than 99 or those pages with 3 digits

Since there are 189 digits for pages with less than 3 digits, we can subtract 189 from 1629 digits to find the number of pages with 3 digits

1629 − 189 = 1440

1440 represents the pages with 3 digits, so number of pages with 3 digits = 1440/3 = 480

Thus, total number of pages = 480 + 90 + 9 = 579 pages

Puzzle #4 solution:

Pizza cut into 11 pieces


Puzzle #5:

The trick is to find out how much money you make in 30 days if you get 1 cent the first day, 2 cents the second day, 4 cents the third day, and so on... Day 1: 1 cents

Day 2: 2 cents

Day 3: 4 cents

Day 4: 8 cents

Day 5: 16 cents

Day 6: 32 cents

Day 7: 64 cents

Day 8: 128 cents

Day 9: 256 cents

-------

-------

-------

-------

Keep mutliplying by 2

-------

-------

-------

-------

Day 30: 536,870,912 cents

536,870,912 cents/100 = 5,368,709.12 dollars and 5,368,709.12 is bigger than 5,000,000

Therefore, you are better off taking 1 cent the first day, 2 cents the second day, 4 cents the third day, and so on... until the 30th day

Puzzle #6:

If the blue rectangle represents the table and the red circles represent dishes, here is the solution

Dishes around a table


Are you not tired yet with these fun math puzzles? Read on...

Puzzle #7:

First, let us clarify what we mean by 9 before it and 9 after it.

Suppose AB is the two-digit number. The meaning of 9 before the two digit number is 9AB and the meaning of 9 after it is AB9.

9AB can be written as B + 10A + 900

AB9 can be written as 9 + 10B + A × 100 = 9 + 10B + 100A

According to the problem, 9AB = 3AB9 + 3

Substitute B + 10A + 900 for 9AB and 9 + 10B + 100A for AB9

B + 10A + 900 = 3(9 + 10B + 100A) + 3

B + 10A + 900 = 27 + 30B + 300A + 3

B + 10A + 900 = 30 + 30B + 300A

900 - 30 = 300A - 10A + 30B - B

870 = 290A + 29B

Let A = 3, then 870 = 290 × 3 + 29B

870 = 870 + 29B

0 = 29B

B = 0

The number AB that we are looking for is 30.

If we put a 9 before 30, we get 930 and if we put a 9 after 30, we get 309.

Notice that 930 = 3 × 309 + 3

Puzzle #8:

In a family with 4 siblings, John is older than Mary, Peter is younger than John, Mary is older than Peter, and Sarah is older than John. Who is the second oldest in the family? Who is the youngest? This puzzle. You solve it!

If you love these fun math puzzles, stay tune. This page will be updated with fun math puzzles on a regular basis!

Other fun math puzzles

Checkerboard puzzle
How many squares are there in a 8 × 8 checkerboard? This puzzle will really challenge your visual/spatial intelligence. Rated mature only. Just kidding!

Triangular numbers
This one will teach you about triangular numbers and how to derive the formula to get the nth triangular numbers

Palindromes
This lesson will teach you how to find palindromes with a simple algorithm

Number of segments between points
This lesson will teach you how to count the number of segments between n points

Cryptarithms
This lesson will teach you how to solve cryptarithms

Leap year
What is a leap year? This topic requires only basic math. However, the level of sophistication will amaze or puzzle you!

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