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1: 626 minus 170, plus 132. The third even number. 434 times two. 2: Its half is fifteen. 1886 divided by two. One half of 120. 3: Term that in Fibonacci series goes after second 1. Two cubed plus one. You will get double when multiplying by this number. In Roman numerals is VII. 4: 136 plus 226. 158 plus one hundred. 5: The double of twenty-one plus one. Nineteen times five, minus nine. 6: 124 plus 627. 5980 divided by ten. 7: Three squared minus one. Term that in Fibonacci series goes after 2 and before 5. 10% of 80. Its half is four and one half. 8: One third of 69. 328 minus 280, plus 163. 285 divided by five. 9: 8,6 times one hundred. 50% of four. 49200 divided by one hundred, plus seventy.


1: 674 minus 103, minus thirty-nine. Angles in a trapezium. 849000 divided by one thousand, minus twenty-one. 2: Seventy-four plus six. 456 minus 119. In Roman numerals is XXXVI. 3: In binary representation is 1000. Faces in a pentagonal pyramid. The square root of 25. Number that increases tenfold when it is to the right of other number. 4: 1336 minus 344. 0,132 times one thousand. 5: 640 divided by ten. Three times eight minus twelve. 6: 2992 divided by eight, minus fifty-two. 107 plus 553, minus seventy-nine. 7: Three squared minus one. Two to the power two plus one. Three squared. In binary representation is 101. 8: Eleven plus fifty-five. Fifty-one plus 933, minus ninety-six. One third of 168. 9: 6080 divided by eight, plus forty-seven. Three times two. 355 plus 679, minus sixty-two.


  • To enter numbers choose a square by clicking on it.
  • Only one number per square is allowed.
  • Once a number is entered, the cursor will jump to the next square for your convenience. If “across” definitions are selected, the next square will be the one to the right. If “down” definitions are selected, the next square will be the one below.
  • You can use the arrow keys to move inside the crossword grid.
  • You can use the CHECK button to see if the squares have the correct number. Incorrect numbers will temporarily appear in red.
  • Click on the CLEAR button to delete the numbers in all the boxes automatically.
  • Click on the NEW CROSSWORD button for play a new crossword puzzle.


  • It is better to try and do mentally the arithmetic operations in the definitions. It is true that some of them may be difficult, but just by trying you will be exercising your mind.
  • If arithmetic operations turn up to be complicated, it is better to use paper and pencil to solve them. If you use a calculator operations will be too easy, there will be no mental exercise and solving the game will be useless.
  • Searching for shortcuts or tricks for calculations is also beneficial because you will be using your memory at the same time as you employ strategies and exercise logical thinking. For example, it is easier to mentally add 1533 plus 2257 if we first do 1000 + 2000 = 3000, then 500 + 200 = 700 + the previous result = 3700, after that we do 30 + 50 = 80 + the previous result = 3780 and finally we do 7 + 3 = 10 + the previous result = 3790. You can search for more tricks or calculation techniques in Google.
  • If numbers in an operation are too long you may be able to deduce part of the result at a guess. For the rest of the digits you can use the definitions of the numbers that cross the number in question. Let’s consider, for example, 35637 minus 11894. We will immediately realise without any calculation that the first digit of the result is going to be 2 and the last is going to be 3 (2xxx3). The other three digits will be probably deduced with the definitions of the numbers that cross the number we need to find.