Ending 5

Ending 5 is a number game for young players. Each puzzle, system will randomly provide 4 integers between 1 and 9. The player needs to use four basic mathematical operators (+, -, *, /) and parenthesis to make an expression with the four numbers so that the result of the expression is an integer ending with 5. Note that it is not required to use all the spaces in the expression.

In most cases, this game is not difficult and the solution is not unique. For example, suppose the four integers are 1, 3, 6, 9. "(6-1)*3*9" is a correct answer, "3-1+9-6" is another correct answer.

iPhone/iPad app is available in Apple App Store.

How to play,

To move an operator or a parenthesis into the expression,
1. players can tap an operator/parenthesis once to select it (a gray box appears on it) and then tap the target spot once in the expression, or
2. players can tap an available spot once to select it and then tap an operator/parenthesis once, or
3. players can drag an operator/parenthesis to the target spot in the expression.

To cancel (remove from expression) an operator or a parenthesis,
1. players can drag it out from the expression, or
2. tap the operator/parenthesis once and then tap the same operator/parenthesis at the original place.

To switch two elements in the expression,
1. players can drag one element onto another element, and release when the other element pops out, or
2. players can tap one element and then tap another element.

To insert an element into the expression, players can drag and move it to the place between two elements. Release when the two elements shrinks.