FOUR 4'S
RULES
Find all the numbers from 0 to 16 using the digit 4 only four times and the operations + , – , x , / , ( ) and
Example: 4 – 4 + 4 – 4 = 0
FOUR 4'S
TOOLKIT
“+” : plus (for addition) -> a sum
“– ” : minus (for substraction) -> a difference
“ x ” : times (for multiplication) -> a product
“/” : divided by (for division) -> a quotient
“ ( “ and “)” : left (or opening) and right (or closing) brackets/parenthesis
““ ” : square root
“=” : is equal to/equals/gives

RIDDLES
FROM http://matoumatheux.ac-rennes.fr/Anglais/numA/entier/Anglais/devinettesA.htm
1) I am a number made of 5 digits.
My tens digit is the sum of its two neighbours.
My units digit is half of my hundreds digit.
My thousands digit is 6.
My hundreds digit is the same as my thousands digit.
My first digit is 3.
Who am I?
2) I am a 6-digit number.
All my digits are odd.
My tens digit is greater than my thousands digit.
My units digit is one third of my hundreds digit.
My thousands digit is 7.
My hundreds digit is the same as my tens digit.
My first digit is 5.
My ten-thousands digit is different to all the others.
Who am I?
3) I'm a four-digit number.
The sum of my digits is 18.
My units digit is the double of my tens digit.
My hundreds digit is the sum of my tens and my thousands digits.
If we add 6903 to me, we obtain the same number as me but backwards.
Who am I ?

FOUR 4'S
SOLUTIONS
0 = 4 - 4 + 4 - 4
1 = (4 * 4) / (4 * 4)
2 = 4 * 4 / (4 + 4)
3 = (4 + 4 + 4) / 4
4 = 4 + 4 * (4 - 4)
5 = (4 + 4 * 4) / 4
6 = 4 + (4 + 4) / 4
7 = 4 + 4 - 4 / 4
8 = 4 + 4 + 4 - 4
9 = 4 + 4 + (4 / 4)
10 = 4 + 4 + 4 / 4
11 = 44 / (4 * 4)
12 = (4 + 44) / 4
13 = 4 + (44 / 4)
14 = 4 + 4 + 4 + 4
15 = 4 + 44 / 4
16 = 4 + 4 + 4 +4
RIDDLES
SOLUTIONS
1) 36,693
2) 517,993
3) 1,548