# DAY/DYDD/GIORNO/NAP 159: T he Main Challenge

Can you make all three lines work out arithmetically by placing the numbers 1, 2, 3, 4, 5, 6, 10, 11 and 12 into the nine gaps below?

◯   +   ◯   =   ◯
◯   +   ◯   =   ◯
◯   +   ◯   =   ◯

If you enjoy this type of number puzzle, click Mathelona which will give you full information about our pocket book challenges. 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

Which number, when 10 is added to it, becomes a multiple of 7? The Lagrange Challenge

Lagrange’s Four-Square Theorem states that every integer can be made by adding up to four square numbers.

For example, 7 can be made by 2²+1²+1²+1² (4+1+1+1).

Show how you can make 159, in SIX different ways, when using Lagrange’s Theorem. The Mathematically Possible Challenge

Using the three digits 35 and 8 once each, with + – × ÷ available, which is the ONLY number it’s possible to make from the list below?

10    20    30    40    50    60    70    80    90    100

#10TimesTable The Target Challenge

Can you arrive at 159 by inserting 146 and 10 into the gaps on each line?

•  (+)²–(²+²) = 159
•  ◯³+²+◯ = 159   