Ever feel sluggish or tired, like your brain can’t function first thing in the morning?  Then why not give it some exercise with a brain puzzle or two?  See if you can work out the answers to these cool math puzzles.  The answers are at the bottom of the page.

  1. Find a 10-digit number where the first digit is how many zeros are in the number, the second digit is how many 1s are in the number etc. until the tenth digit is how many 9s are in the number.

 

  1. Use 8 exactly eight times to make 1000 using + – * /

 

  1. How do you write 23 using only the number 2?

34 using only the number 3?

56 using only the number 5?

100 using only the number 9?

 

  1. A man weighing 14 stone and his two sons weighing 7 stone each are stranded on an island. All they have to do to get off the island is get in a small boat, but it only holds 14 stone. How can the man and his sons get off the island?

 

  1. Do not use a calculator for this one!

 

Take 1000 and add 40 to it. Now add another 1000 to it.

Now add 30. And another 1000.

Now add 20. Now add another 1000. Now add 10.

 

What is the total?

Answers

  1. 6210001000
  2. 888 + 88 + 8 + 8 + 8/ (8(8(8+8)-(8+8)/8))-8/ 8(8×8+8×8)-8-8-8 – you may also have your own unique solution
  3. Using fractions of course! 22+2/2=23, 33+3/3=34, 55+5/5=56, 99+9/9=100
  4. The two sons get in the boat and go back to shore, one jumps out, the other rows back to the island and gets out. The dad gets in and rides back to shore where he jumps out and the other son gets back in. The son goes back to the island and collects the other son and together the two of them row back to the safety of the shore!
  5. 4100, not 5000 as you might have thought. Now try it on a calculator!