## What number am I? – Prime numbers and perfect squares

Math Teaser I am a perfect square. My square root is a prime number, less than 100, and the digits of the square root add up to a perfect square. My own digits add up to a prime number. [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] To solve this, we need to first determine what the options for […]

## Reverse Calculation

Math Teaser! A number is divided by five. The result is divided by three, for a ﬁnal result of two. What was the original number? [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] To find the answer we simply do the opposite calculations in the reverse order. We start with 2.  If a number was divided by 3 to […]

## Rectangle

Math Teaser! If a rectangle has an area of 192 square meters, and the length is three times longer than its width, what are the length and width? [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] The area of a rectangle is found by multiplying the length by the width. (l x w)  If we call the width x, […]

## Steps in a mile

If I were to start a new exercise program where I double my previous day’s steps each new day, on which day of the program will I first walk a full mile? I will start with 1 step on Day 1 and all of my steps are 2 feet long. Bonus: On that day, how many steps beyond a mile […]

## 25 Cent Coin Combinations

Math Teaser How any combinations of US coins are there that add up to 25 cents? [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] There are 12 possible coin combinations of the penny, nickel, dime, and quarter that add up to 25 cents. These coin combinations are easier to count if you realize that you will not be able […]

## A Sequence

Math Teaser! If the first five terms of a sequence are 0, 2, 8, 18, 32 what would be the value of the tenth term? [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] Start by looking at how each term in the sequence is related to the others. Since the terms grow bigger and bigger by an increasing margin […]

## Equation Generation 3

Math Teaser Using the numbers 2,3,4,5,6, and 8 find two 3 digit numbers that add up to 1000. (There is more than one correct answer!) [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] Again, there are several solutions to this one, and below are a few – there may be others… 562 + 438 = 1000 462 + 538 […]

## Equation Generation 2

Math Teaser Using the numbers 8,8,6,7, and 3 create an equation that equals 1. [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] There are several solutions, and below are only a few – the trick is to make sure the Order of Operations is correct. 3 – (8/8) – (7 – 6) = 1 (((6/3) x 8) – 8) […]

## What Number am I? – Square, cube, prime digits

Math Teaser I am a 3 digit number whose product of my digits is equal to 144. Of my 3 digits, one is a cube, one is a square, and one is a prime. If the six numbers that meet these criteria are listed in increasing order, I am fifth in the list. [doptoggle title=”Click Here to see the Solution!!!” […]

## What Number am I? – Combination of digits

Math Teaser I am 3 digits. My digits add up to 10. The product of my digits is 20. I am an odd number. The digit in the hundreds place plus the digit in the tens place equals the digit in the ones place. The smallest digit is in the middle. [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] […]

## Football Score

In football, how many possible scoring combinations are there that would result in a team having 10 points on the scoreboard? (Ignore defensive points on PAT attempts) [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] The possible scores to consider are a safety (2 points), a field goal (3 points), a touchdown with no extra-point/PAT or two-point conversion (6 […]

## Equation Generation

Using the numbers 9, 7, 3, and 4 create an equation that equals 2. [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] There are several solutions, and below are only a few – the trick is to make sure the Order of Operations is correct. (9 – 7)/(4 – 3) = 2 (9 – 3)/(7 – 4) = 2 […]

## Two Coins

I have two US coins that combine to total 35 cents. One is not a dime. What are the coins? [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] The trick here is in the wording (ok, so it isn’t really a math teaser…). Only one of the coins is not a dime, not both! One is not a dime, […]

## A Dice Combination Problem

If you have two 6-sided dice, numbered 1-6, how many dice combinations are there that do not include the number 5? Note that a 1 and 6 and a 6 and 1 with the two dice are counted as separate dice combinations. [doptoggle title=”Click Here to see the Solution!!!” icon=5 activeicon=6] There are six sides to each die, so to […]