# DAY/DYDD/GIORNO/NAP 261: The Main Challenge

Your task is to make all four lines below work out arithmetically by placing digits from 0 to 9 into the 16 gaps, but each digit can only be used a maximum of twice!

Can you complete this Mathelona challenge?

◯  +  ◯   =    9    =   ◯  +  ◯
◯  +  ◯   =    3    =   ◯  –  ◯
◯  +  ◯   =    8    =   ◯  ×  ◯
◯  +  ◯   =    2    =   ◯  ÷  ◯ The 7puzzle Challenge

The playing board of the 7puzzle game is a 7-by-7 grid of 49 different numbers, ranging from up to 84.

The 1st & 5th rows contain the following fourteen numbers:

2   6   7   9   14   15   16   21   22   40   50   72   81   84

What is the sum of the multiples of 7? The Factors Challenge

Which of the following numbers are factors of 261?

3     5     7     9     11     13     None of them The Mathematically Possible Challenge

Using 58 and 11 once each, with + – × ÷ available, which are the only TWO numbers it is possible to make from the list below?

90    91    92    93    94    95    96    97    98    99

#NumbersIn90s The Target Challenge

Can you arrive at 261 by inserting 1, 2, 3, 4 and 5 into the gaps below?

•  (◯××)²+(◯+◯)² = 261   