# ninedigits workshop

4.21 PUZZLE GAME

The game is about to find solutions sorting the digits from 1 to 9 in a square of 3 * 3 where the sum of the numbers of the two top rows is equal to the bottom row.

This puzzle is aimed on reflection on the commutative property of addition.

This program is aimed at reflecting on the addition. The goal is to find results that meet the primary condition. We must be aware that after obtaining a correct result can be achieved more easily results having in mind the properties of the sum.

Interaction
To swap two digits must be done tap on each digit then the digits change the color and the exchange occurs.

From
http//www.nummolt.com/obbl/ninedigits/ninedigitsbasic.html
nummolt - Obbl - Math Toys collection - Mathcats.

Ninedigits has 336 solutions. If the program would be easy for someone then the goal could be to find valid solutions in which a Queen (Lady) could travel chess boxes 1 to 9 making right moves to this tab. According to our analysis there are 3 solutions of this type. You can also look under the same condition but with the Tower (Rock) of chess. This combination of conditions has only one solution. The program clearly shows the production of these special results.

As a safety mechanism the delete button only works when the program displays a correct solution of the problem.

Registered in Math Tools (MathForum)
http//mathforum.org/mathtools/tool/234619/
Classified for courses
Math 5 Addition Mental math Commutative
Math 6 Addition Mental math Commutative
Math 7 Mental math Commutative

Aligned with Common Core Math

Grade 3 Â» Number & Operations in Base Ten
CCSS.Math.Content.3.NBT.A.2
Fluently add and subtract within 1000 using strategies and algorithms based on place value properties of operations and/or the relationship between addition and subtraction.

Origin of the game
The ninedigits is based on an new idea described in a Martin Gardner's. mathematical book of diversions published in 1966.

Nine Digits and the chain of numbers problem
All the right results involve an addition of 3 digits with trading.

Nummolt apps Math Garden Prime Numbers Barn and Numbers Mill

### Video

1.6.3 v.14 sdk29 Update Android 10

### Other versions

1.6.2 released on 04 February 2019 (721 days ago)

### Details and Recent Ratings

Size: 1 MB
Version: 1.6.3 by nummolt
Updated: 05 October 2020 (112 days ago)
Released: 26 September 2012
Installations: more than 10 000
5 Stars: 26
4 Stars: 4
3 Stars: 2
2 Stars: 2
1 Star: 4

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