Perfect Practice Makes Perfect

# Number Puzzle

## Tuesday’s Twister #18 – Number Sense (Order of Operations)

October 25th, 2015 by John Lehet

Here’s another Number Sense Puzzle. Today’s puzzle centers around another fundamental skill that gives many students a really difficult time – Order of Operations. This is geared to younger puzzlers to help them improve their Order of Operations skills. As always, let me first give a general introduction. There will be 8 statements each corresponding to a number. You have to use the numbers 0 through 9 once and only once to fill in the correct number for each statement. You will need to use and develop your deductive problem solving skills in order to correctly place the numbers. Since there are only 8 answers and 10 numbers (0 through 9), some of the answers will require two digits. In this puzzle, some of the answers will be negative, that’s no problem, just make sure the digits use 0 through 9 once and only once.

I created an interactive puzzle that will automatically check your answer and provide feedback. I also created a pdf file that can be used in classrooms or with pencils for those so inclined. The goal is to have fun and challenge yourself.

I hope you enjoy these puzzles. If you find these interesting, Click Here for a selection of more Number Sense puzzles that I’ve created. I will be adding to the selection over time. Good Luck and pass the puzzles onto others who may enjoy them!

## Tuesday’s Twister #17 – Number Sense (Negatives)

October 22nd, 2015 by John Lehet

Here’s a puzzle that I introduced back in December called Number Sense Puzzles.  They are geared for younger puzzlers to help them improve their number sense.  Let me first give a general introduction. There will be 8 statements each corresponding to a number.  You have to use the numbers 0 through 9 once and only once to fill in the correct number for each statement.  You will need to use and develop your deductive problem solving skills in order to correctly place the numbers.  Since there are only 8 answers and 10 numbers (0 through 9), some of the answers will require two digits.  In this puzzle, some of the answers will be negative, that’s no problem, just make sure the digits use 0 through 9 once and only once.

I created an interactive puzzle that will automatically check your answer and provide feedback. I also created a pdf file that can be used in classrooms or with pencils for those so inclined. The goal is to have fun and challenge yourself.

Today’s puzzle is all about adding and subtracting negatives. I’ve found that this is an area that gives many students a really difficult time. It looks easy, but remember to take your time so you use each number once and only once!

I hope you enjoy these puzzles.  If you find these interesting, Click Here for a selection of more Number Sense puzzles that I’ve created.  I will be adding to the selection over time. Good Luck and pass the puzzles onto others who may enjoy them!

## SAT Math Blast – #13

October 2nd, 2015 by John Lehet

Here’s the 13th SAT Math Blast for those preparing for the SAT this Fall. Just like the last SAT Math Blast, today’s questions are all word problems in the easy to moderate difficulty range. Acutally, I’ve developed ten questions very much like those in SAT Math Blaster #12. Practice and redundant practice especially will help you master word problems.

 Topic – Algebra Level – Easy/Moderate Questions – 10

Remember, just select “START” to give it a try. Use the “NEXT” and “PREV” buttons to navigate and when you’ve answered all of the questions, select “COMPLETE”. You’re results will be posted. Also, you will be able to return to any of the questions to review (just select the question number in the results window).

As always, I hope you enjoyed this post. Please pass it onto others who may enjoy and please click LIKE below if you like it! (you need Adobe Flash in order to interactively run the above exam)

## SAT Math Blast – #12

September 26th, 2015 by John Lehet

Here’s the 12th SAT Math Blast for those preparing for the SAT this Fall. Today’s questions are all word problems in the easy to moderate difficulty range.

 Topic – Algebra Level – Easy/Moderate Questions – 10

Remember, just select “START” to give it a try. Use the “NEXT” and “PREV” buttons to navigate and when you’ve answered all of the questions, select “COMPLETE”. You’re results will be posted. Also, you will be able to return to any of the questions to review (just select the question number in the results window).

As always, I hope you enjoyed this post. Please pass it onto others who may enjoy and please click LIKE below if you like it! (you need Adobe Flash in order to interactively run the above exam)

## SAT Math Blast – #9

September 15th, 2015 by John Lehet

Here’s the ninth SAT Math Blast for those preparing for the SAT this Fall. Today’s questions all deal with Algebra!

 Topic – Algebra Level – Moderate Questions – 10

Remember, just select “START” to give it a try. Use the “NEXT” and “PREV” buttons to navigate and when you’ve answered all of the questions, select “COMPLETE”. You’re results will be posted. Also, you will be able to return to any of the questions to review (just select the question number in the results window).

As always, I hope you enjoyed this post. Please pass it onto others who may enjoy and please click LIKE below if you like it! (you need Adobe Flash in order to interactively run the above exam)

## SAT Math Blast – #7

September 11th, 2015 by John Lehet

Here’s the seventh SAT Math Blast for those preparing for the SAT this Fall. This is a follow up to SAT Math Blast #3, as it has similar questions.

 Topic – Numbers and Operations Level – Easy Questions – 10

Remember, just select “START” to give it a try. Use the “NEXT” and “PREV” buttons to navigate and when you’ve answered all of the questions, select “COMPLETE”. You’re results will be posted. Also, you will be able to return to any of the questions to review (just select the question number in the results window).

As always, I hope you enjoyed this post. Please pass it onto others who may enjoy and please click LIKE below if you like it! (you need Adobe Flash in order to interactively run the above exam)

## SAT Math Blast – #5

September 8th, 2015 by John Lehet

Here’s the fifth SAT Math Blast for those preparing for the SAT this Fall. Today’s problems are all number line related problems. The questions are in the Easy/Moderate level and in the Numbers and Operations category:

 Topic – Numbers Level – Easy/Moderate Questions – 10

Remember, just select “START” to give it a try. Use the “NEXT” and “PREV” buttons to navigate and when you’ve answered all of the questions, select “COMPLETE”. You’re results will be posted. Also, you will be able to return to any of the questions to review (just select the question number in the results window).

As always, I hope you enjoyed this post. Please pass it onto others who may enjoy and please click LIKE below if you like it! (you need Adobe Flash in order to interactively run the above exam)

## Tuesday’s Twister #13 – Prime Numbers

May 19th, 2015 by John Lehet

“There are three kinds of people: Those that make things happen, those that watch things happen and those that wonder what happened. ” – Agent Garbo (Juan Pujol Garcia)

Prime numbers are everywhere and they are really easy to understand.  There are just two simple rules to follow:

• – a prime number is a positive integer greater than 1
• – a prime number is evenly divisible by only 1 and itself

That’s pretty straight forward.  Many people assume 1 is a prime number, but by definition, it’s not.  It’s important to realize and remember this when dealing with primes.  Also, 2 is the only even prime number, as all other even numbers are divisible by 1, 2 and itself.

Here’s a couple of prime number puzzles to start you off.

puzzle 1: What is the smallest 2-digit prime number in which both digits are prime and their sum is prime?

puzzle 2: What is the largest 2-digit number in which both digits are prime and their sum is prime?

Let’s look at an example number, say 73.  73 is a prime number and it’s digits, 7 and 3 are both  prime.  However, the sum of the digits 7+3 equals 10, which is not prime.  So, 73 will not work for either puzzle 1 or puzzle 2.

Once you solve the first two puzzles, you should have a good handle on prime numbers.  I recommend listing all of the prime numbers less than 100.  To make it a bit more challenging, let’s look at 3-digit numbers.

puzzle 3: List all 3-digit numbers that have prime numbers for all three digits.

puzzle 4: Of the numbers listed in puzzle 3, list the numbers in which the digits sum to a prime number.

puzzle 5: Of the numbers listed in puzzle 4, which of the numbers are themsleves prime?

Let’s look at an example 3-digit number, say 235.  the digits, 2, 3 and 5, are all prime numbers.  However their sum, 2+3+5, equals 10, which is not a prime number (so it doesn’t work for puzzle 4).

Good luck with the puzzles and have fun.

## Tuesday’s Twister #12 – Sequences

May 13th, 2015 by John Lehet

“Lost time is never found again.” – Ben Franklin

When working with students in elementary school, I like to talk about sequences or number patterns.  I often present them with the start of a sequence, say the first three numbers.   I then ask the class to give me the next term (or number) in the sequence.  Letting everyone in the class mull it over for a bit, I ask for the pattern (the code essentially) and the next few numbers.  When I first did this, I was amazed!  I had a sequence in mind, but the students kept giving different, yet very viable sequences.  Not only that, they could justify their answers by supplying the “code” for the sequence.  I quickly realized that with just three numbers at the start of a sequence, the possibilities were plentiful.  It was quite the challenge for the students also.

So, I started doing this as a “break the ice” activity with classrooms.  We would use the same three numbers again and again, and see how many different (yet viable) sequences could be made.  When they give me a sequence and its corresponding justification, I would say “great, let’s find another” and erase it leaving only the first three “seed numbers” that I had originally written.  I  would then ask them to give me another different sequence and the whole thing would start over again.  Each time I do this, I am still amazed at how many different sequences they come up with and how challenging they find it.  Here’s the start of a sequence for you to try …

## Here’s three numbers that start a sequence:    2, 3, 5, . . .

What do you think the next number can be?  How about the number after that?  Remember, it has to follow a pattern, so you can easily find each successive number by applying the pattern.

I’ve given this pattern to numerous classrooms.  Each time,  they came up with a variety of different answers, all of which make a valid sequence.  For the next number, classes have given 7,  some have given 8 while others have given 14.  In all, from all of the classes, I have received 9 different sequences that these three numbers can generate (and there’s even more!).

My challenge to you is to find as many different sequences that can be generated using the first three numbers  2, 3, 5.  Remember don’t just come up with the sequence, but identify the pattern that it follows.  Challenge yourself to see if you can find nine different sequences.  Good luck, have fun and challenge others, the more the merrier!

## Tuesday’s Twister #11 – Number Circuits

May 5th, 2015 by John Lehet

“Go fast slowly” – Clarence Stephens

Number Circuits are an original puzzle that I came up with a few years ago.  They are number sense puzzles that require you to arrange a set of numbers in a designated pattern.  I used magic squares as a theme using shapes other than squares. In all, I was able to develop over 200 puzzles all with this same theme.  Fortunately, Mindware liked the puzzles and published two books.  I was pretty excited (and still am).  The books differ in difficulty, although neither set of puzzles are too difficult (although all puzzle are challenging when you can’t solve them!).  Below are four puzzles, two from each book.  I believe they’re representatve of each collection and Number Circuit puzzles in general.  Click each picture to open a full sized pdf image of each puzzle in a new window.

 from Number Circuits A from Number Circuits B

As always, I hope you enjoyed these puzzles. Please pass them onto others who may enjoy them and please click LIKE below if you like them!

MIndware currently has the books for sale for only \$3.95 (that a 69% savings!).  If interested in purchasing either book just click below:

Number Circuits A (Beginner Puzzles)