Page 11 - NUMINO Challenge_D1

1 Four Fours and Target Numbers

Basic Concepts Four Fours

Four Fours is a puzzle in which four 4’s and operation symbols
( , , , ) are used to form equations that make numbers from 1 to 100.

44 44 1 (4 4) (4 4) 2
(4 4) (4 4) 1 4 4 (4 4) 2
44441 4 {(4 4) 4} 2
44441 4 {(4 4) 4} 2

Example Use four 4’ s, operation symbols ( , , , ), and parentheses
to form equations that make the numbers 3, 5, 8, 10, 15, and 20.

Class Notes

You can use two 4' s to make the following numbers:
44, 4 4 8, 4 4 0, 4 4 16, 4 4 1.
Use the equations above to form those shown below.
4 4 4 4 8, 4 4 4 4 15
Use three 4' s to make 4 4 4 12, 4 4 4 20, 44 4 40, and 4 4 4 5.
Add one more 4 to form the equations shown below.
(4 4 4) 4 3, (4 4 4) 4 5,
(44 4) 4 10, (4 4 4) 4 20

Try It Again Use four 9' s, operation symbols ( , , , ), and parentheses
to form equations that make the numbers 3, 8, 9, 10, and 20.

9 9 9 93
9 9 9 98
9 9 9 99
9 9 9 9 10
9 9 9 9 20

8 NUMINO Challenge D1