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Nines Challenge Puzzle

The Nines Challenge is a fun number-based puzzle which challenges you to make various results using exactly four nines as well as your choice addition, subtraction, multiplication, and division as well as grouping symbols.

What is the Nines Challenge?

Using exactly four nines, add arithmetical symbols between the nines to make each of the target numbers. You may use plus, minus, times, and divide symbols, as well as parentheses and brackets for grouping.

This nines number challenge is a fun twist on the classic Four Fours Puzzle.

Source of Challenge

I discovered this challenge based on the number three in Pierre Berloquin’s 100 Numerical Games book.

I picked up a copy of the book several years ago at Goodwill, and it has inspired numerous classroom activities over the years. Previously, I have blogged about the 20 x 9 Challenge, the Twos Challenge, the Threes Challenge, the Fours Challenge, the Fives Challenge, the Sixes Challenge, the Sevens Challenge, and the Eights Challenge.

Ideas for Using in Class

I have previously used this challenge with students on the first day of school as part of the Twos to Nines Challenge. I put challenges up for each of the numbers from two to nine around the classroom for students to tackle on our dry erase boards.

fours challenge

I have since created a printable PDF template for the nines challenge that already has the four nines written in. Students just have to add various mathematical symbols to make each expression mathematically correct.

Nines Challenge Puzzle Screenshot.

For puzzles like this, I usually only print a class set of copies in order to save paper. I prefer to give my students these puzzles in a dry erase pocket. You can pick them at places like Dollar Tree and Target’s Dollar Spot, but I’ve found they are much cheaper when you buy a classroom set from somewhere like Amazon.


dry erase pockets

I cannot imagine teaching math without my dry erase pockets! They instantly make any activity more engaging and save me countless hours at the copy machine since I can use the same class sets of copies year after year.

Here are my current go-to recommendations:

  • 8.5 x 11 Inch Dry Erase Pockets from Puroma
  • 11 x 17 Inch Dry Erase Pockets from C-Line Products
  • Expo Dry Erase Markers

If you don’t have a classroom set of dry erase pockets, you could also use heavy duty sheet protectors. But, I highly recommend investing in a classroom set of the pockets since they are so much more durable.

Puzzle Solutions

I intentionally do not make answers to the printable math puzzles I share on my blog available online because I strive to provide learning experiences for my students that are non-google-able. I would like other teachers to be able to use these puzzles in their classrooms as well without the solutions being easily found on the Internet.

However, I do recognize that us teachers are busy people and sometimes need to quickly reference an answer key to see if a student has solved a puzzle correctly or to see if they have interpreted the instructions properly.

If you are a teacher who is using these puzzles in your classroom, please send me an email at with information about what you teach and where you teach. I will be happy to forward an answer key to you.