How Much Water to Fill My Pool?

Do you ever wonder how many gallons of water it would take to fill a medium size above- or below-ground swimming pool?  If you are similar to the average person, you have likely thought about it once or twice in your lifetime, but probably not much more than that.  Perhaps during one of your famous cannonball dives and several gallons are displaced out of the pool, you may have thought about it, in a competitive way!

The formula is fairly simple, especially if you are familiar with a few Math terms.  Let's look at a couple examples.

1.) How many gallons of water does it take to fill a circular swimming pool that measures 20ft across and has an average water depth of 5ft?
Solution:
* Find the area of the surface, which = Pi (3.14) x Radius squared.
3.14 x 24 x 24 = 576 sq.ft.
* Find the volume of the pool by multiplying the top surface area times the depth of the pool, which is 5 ft.
576 sq.ft  x 5ft = 2880 cubic ft.
* Knowing that there are approximately 7.5 gallons of water per cubic foot, you can multiply the volume times the number of gallons of cubic feet to know how many gallons you need.2880 cubic ft.  x  7.5 gallons per cubic ft. = 21,600 gallons!


Take a look at another example, this time the pool is rectangular shape, and measures 16ft x 36ft and is 5ft deep throughout the pool.  How much water does it take to fill the pool?
Solution:
* Find the area of the surface which is 16 x 36 = 576
* Find the volume of the pool by multiplying the top surface area  x  the depth, which is 576 x 5 = 2880 cubic ft.
* Multiply the volume  x 7.5, which is 2880 x 7.5 = 21.600 gallons!

Did you notice something?  Both pools with different shapes and different dimensions require the same number of gallons to be filled!  Next time you are trying to decide which pool to build at your new home, you will know that there is more than one shape of a pool that can have the same overall dimensions and water usage!

For those of you who want to know how many Liters it would take to fill the pools in our examples, you can simply multiply 21,600 gallons x 3.78 L per gallon.  It would take 81,648 L to fill each pool! 

Happy swimming, everyone! 

No Boss Will Ever Say This!

I saw something today, and it caused me to realize once again why I do what I do, but even more importantly, that I truly enjoy being a Math Teacher and helping others learn.

The sign read, "I need to hire employees who can't do Math--said no boss ever!"

Family and friends, it is never too late to learn new skills, or to brush up on the ones that you need to re-learn.  I have created a new blog today helpmedothemath.blogspot.com which is a blog similar to this one, but you can directly ask me a Math question and receive help.

Receive Change Like a Boss!

Do you go to the market or restaurant, and frequently receive a large number of coins and small bills, but wish you knew the trick to receive larger denominations of both?  I remember as a youth watching my mom and dad make purchases at the market and be able to adjust the amount they received in change, quickly knowing how to make an adjustment to the amount they gave the cashier to pay for their groceries.

In my adult life, I have been instructed by a cashier from time to time that it was too late to make an adjustment to the amount that he/she had expected to receive from me, primarily in the form of a whole dollar bill, perhaps a $5, $10, or $20.  I have been told by cashiers also, that they have been advised to provide the exact amount of change that the 'computer told them to give' and to not deviate from it.  The trick and very first step is being confident and ready and to not show the cashier the amount you are paying until he/she is ready to receive your payment.

Let's take a look at a real-world example and see how you can adjust the amount of change you receive.

You are at Dave's Deli and have purchased a turkey sandwich and a large drink.  The total due is $7.36, and you are paying cash for your purchase.  Let's assume you have a $20 bill, a $10 bill, and (3) $1 bills, and the following coins: (3) Quarters, (1) Dime, and (4) Pennies.  There is more than one solution to the amount that you may give Sondra, the deli's ace cashier. 

Knowing that you don't have the exact change to give, here are some possible scenarios:

a.) Simply give her a $10 bill, forgetting that you have several coins in your pocket, and expect to receive $2.64 in change from Sondra. 
b.) You remember that in addition to the $20, $10 and few $1 bills, you have several coins in your pocket.  You quickly decide to pay her $10.36 and she returns $3 in one dollar bills.
c.) Sondra sees that you have some pennies in your hand, and she asks you to give her one penny in addition to the $10, making the total amount received $10.01.  You are thinking to yourself, "Why is she asking me for an extra penny, when $10 is more than enough to cover your sandwich and drink?"
Sondra, seeing the confused look on your face, quickly explains that instead of returning $2 and $0.64 in coins, by giving her the extra penny, she now owes you change of $2.65 which simplifies the Math, saves her 4 pennies for the next customer, and you don't have to carry around extra coins in your pocket. 
d.) While you were in line to pay for your sandwich and drink, you just remembered that you hadn't purchased gifts for your 5 year old twin nephews' birthday party later in the afternoon.  Not having time to purchase a gift, you decide to give each twin $10 in cash.  How will you handle this transaction?  You're now having one of those "Aha Moments" and know exactly how to masterfully receive the perfect amount of change, to make life simple for Sondra, to decrease the amount of coins in your pocket, and to have enough cash for your birthday gifts. 
* Give Sondra your $20 and (2) $1 in addition to (1) Quarter, (1) Dime, and (1) Penny, which is a total of $22.36.
* Sondra is impressed with your astute Mathematics computation, and she returns a $10 and a $5 bill to you!
You win!  Congratulations!  You have successfully decreased the amount of coins in your pocket, and have made life easy for Sondra, and were able to place $10 in each birthday card for your twin nephews!   

A Little Trick Using the Associative Property of Multiplication

A Little Trick Using Associative Property of Multiplication

Earlier this week, we reviewed the Associative Property of Addition.  The Associative and Commutative Properties were the two properties that I had the most difficult time sorting out, for some reason.

As I teach my students each day, I encourage them to find a special way to memorize certain principles and formulas. 

Let's take a closer look at the Associative Property of Multiplication.  For many of us, we have many activities throughout life and we like to associate with certain friends as we enjoy those activities.  There are those other activities that we enjoy, but we prefer to be with other groups of friends.

The Associative Property works very similarly to our social needs, and let's see how we can apply numbers to gain a better understanding.  This property very simply states that if we are multiplying a few numbers, we can multiply them in groups and it doesn't matter which order we place them, the end result will be the same.

Here's a quick example:
1.)  What is the value of 2 x (3 x 5)?
Solution:
Step 1--Do the parenthesis first, (3 x 5) = 15.
Step 2--Multiply by 2.
Answer: 2 x (3 x 5) = 30.

Now, let's regroup the numbers, using the parentheses around the first two numbers and see if we gain the same result.
2.) What is the value of (2 x 3) x 5?
Solution:
Step 1--Do the parenthesis first, (2 x 3) = 6.
Step 2--Multiply by 5.
Answer: (2 x 3) x 5 = 30.

We can easily create and demonstrate several problems, and the principle remains the same.  As long as we are multiplying all of the numbers, we can reposition and regroup the parenthesis, and the result will be the same! 

Create a few examples on your own, and you'll see how easy it is!  Don't forget to share this great information with a friend!

A Little Trick Using Associative Property of Addition

I remember many years ago trying to memorize the handful of Math Properties, and some of them were easier to learn than others.  The Associative and Commutative Properties were the two properties that I had the most difficult time sorting out, for some reason.

As I teach my students each day, I encourage them to find a special way to memorize certain principles and formulas. 

Let's take a closer look at the Associative Property of Addition.  For many of us, we have many activities throughout life and we like to associate with certain friends as we enjoy those activities.  There are those other activities that we enjoy, but we prefer to be with other groups of friends.

The Associative Property works very similarly to our social needs, and let's see how we can apply numbers to gain a better understanding.  This property very simply states that if we are adding a few numbers, we can add them in groups and it doesn't matter which order we place them, the end result will be the same.

Here's a quick example:
1.)  What is the value of 2 + (3 + 5)?
Solution:
Step 1--Do the parenthesis first, (3 + 5) = 8.
Step 2--Add 2.
Answer: 2 + 8 = 10.

Now, let's regroup the numbers, using the parentheses around the first two numbers and see if we gain the same result.
2.) What is the value of (2 + 3) + 5?
Solution:
Step 1--Do the parenthesis first, (2 + 3) = 5.
Step 2--Add 5.
Answer: 5 + 5 = 10.

We can demonstrate several problems, and the principle remains the same.  As long as we are adding all of the numbers, we can reposition the parenthesis, and the result will be the same! 

Create a few examples on your own, and you'll see how easy it is!  Don't forget to share this great information with a friend!

Which Weighs More? Hint: It's Not the Ton of Bricks! 🤓

Many years ago, a teacher asked us which one weighed more, a ton of bricks or a ton of feathers.  The natural response for most of us was to pick the what seemed like the obvious answer, which was a ton of bricks.  Zooming right past the word 'ton' and focusing on the bricks, we knew, in our finite way of thinking, there was no possible way the feathers could weigh as much, or could they?

Thankfully, we were not on a TV Game Show, and didn't forfeit a life-changing Grand Prize by choosing the wrong answer!

As I reflect on this question and many others throughout my life, it often becomes a great teaching moment, as I once again consider the value of instructing others to think before we speak too quickly.

We know that a ton is a ton, whether we are talking about watermelons, gravel, bricks, or feathers.  The correct answer to this riddle is they weigh the same.

Share this riddle and others with your children to sharpen their ability to think for themselves, and to be courageous and creative in their problem-solving skills.

Have a great day, everyone!
😀😀😀😀😀😀😀😀😀

Is it divisible by 5?

Sometimes you need to know if a number is evenly divisible by another number.  Today's hint is quite simple when determining if a number is divisible by 5.  If the dividend (the number being divided) ends with a 0 or 5, then it is always evenly divisible by 5.

Let's look at some examples.

1.) Is 164 evenly divisible by 5?
Solution:
Step 1--Does the number being divided (164) end with a 0 or 5?  No!
Step 2--It is not evenly divisible by 5.  You can certainly divide it, but you will have a remainder of 4.
The answer is 32.8 or 32 4/5.

2.) Is 90 evenly divisible by 5?
Solution:
Step 1--Does it 90 end with a 0 or 5?  Yes.
Step 2--It is evenly divisible by 5.  For every 100, 5 is divisible 20 times.  Since 90 is 10 less than 100, you can conclude that not only is it evenly divisible, but the quotient (the answer to a division problem) is 2 less than 20, which is 18.

3.) Is 10,495 evenly divisible by 5?
Step 1--Does 10,395 end with a 0 or 5?  Yes.
Step 2--It is evenly divisible by 5.  For every 1,000 being divided, 5 is divisible 200 times.  For 10,000 you can conclude that 10,000 is 10 x 1,000 and the answer to the first part of the solution is 10 x 200 = 2,000.
Step 3--Because we know that we can divide 5 into each 100 exactly 20 times, and 395 is 5 less than 400, we can conclude that 395 divided by 5 is simply 20 x 4 -1 = 79. 
Step 4--Add 2,000 + 79 = 2,079.  

Today's tip is easy to understand, and very practical if you need to divide a number by 5 without a remainder.  Create and practice a few examples on your own and share this helpful tip with a friend! 😄

A Late-Night Laugh! 😂

I've often heard mathematicians proclaim that there are only 10 types of people in this world--those who understand binary, and those who don't!
😂😜😁😃😀😉😇😂

Awesome Trick with Percents!

As a child, someone told me that those who are quick with their basic math skills, make successful negotiators.  Whether we realize it or not, we negotiate deals many times throughout our lives.  As I have experienced life, I realize more now than ever before, those words are great advice!
Today's tip relates to learning how to make quick mental calculations of percents that might otherwise require a calculator.

Take a look at this great information!

Suppose you need to calculate 12% of 50.  Of course you can use the decimal form of 12%, which is 0.12, then multiply times 50.  Doing the math, we know the answer is 6.

Here's an alternative way for you to calculate the product of these two numbers much quicker:
Step 1--Instead of calculating 12% of 50, switch the order of the numbers and trade the symbols, also.
Step 2--Calculate 50% of 12.  We all know that 50% of any number is the same as dividing that number by 2.  Very quickly, we know that 50% of 12 is 6.  Same answer, but I'll bet you calculated it much quicker and with great ease!

Consider this real-world example:
Francine's Fashions is celebrating their 48th Anniversary this week, and has reduced all items in the store by 48%.   (To find the savings, you need to know how to find 48% of $25.)
Step 1--Switch the numbers and the signs.  Re-word the question to read, "What is 25% of 48?"
Step 2--Calculate 25% of 48.  We know that 25% of any number is 1/4 of that number.  We also know that we can multiply 48 x 1/4 to get the answer or divide 48/4.
Either way, you can quickly find the answer question without a calculator or paper and pencil!  The answer is 12.

Try it, you'll quickly trade this method for the one you have been using!  Don't forget to share this tip with a family member or friend!  😃

Friday Funny--Gone Without a Tres!

The other day, I watched a magician who was famous for his amazing skills.  He was very confident that he could do something very incredible that night, and he insisted that he could make himself disappear before the count of three, right in front of the audience.
Without hesitation, he began his routine.
"Uno," he said.  Nothing happened.
"Dos," he counted, and poof!  He was gone!
That's right, he disappeared without a tres!
😂😂😂😂😂😂😂😂😂😂😂😂😂😂