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Puzzles

14 December

In July, I posted the Combining Multiples puzzle.
Today's number is the largest number that cannot be written in the form \(27a+17b\), where \(a\) and \(b\) are positive integers (or 0).

13 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10. Today's number is the smaller number in a red box to the power of the larger number in a red box.
+-= 8
- - -
+÷= 3
+ ÷ ×
+×= 120
=
8
=
1
=
8
Tags: numbers, grids

12 December

Here is a list of facts about today's number:
Tags: numbers

10 December

The smallest number that is equal to the sum of its digits multiplied by ten more than the sum of its digits.

8 December

Today's number is the second smallest number that can be written as a×b×c×d×e×f×g×h×i, where a,b,...,i are all integers greater than 1.

7 December

Put the digits 1 to 9 (using each digit once) in the boxes so that the three digit numbers formed (reading left to right and top to bottom) have the desired properties written by their rows and columns.
multiple of 25
today's number
all digits even
multiple of 91multiple of 7cube number
Tags: grids, numbers

6 December

When you add up the digits of a number, the result is called the digital sum.
How many different digital sums do the numbers from 1 to 1091 have?*
* There was a mistake in this question (it previously said 1092). If you answered the typo'd question right, your answer should automatically correct itself to 9 less than it was...

4 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10. Today's number is the product of the digits in the red boxes.
+÷= 2
+ ÷ -
÷-= 5
÷ - ×
-×= 4
=
3
=
5
=
6
Tags: grids, numbers

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