Title.
Double Trouble
Problem Statement
What number can you add
to 129 and subtract from 129 such that the sum of the number and 129 is
twice the difference between 129 and the number?
Problem setup
Restate the problem in your own
words. Discuss mathematical similarities between this problem and other
problems you have solved.
Plans to
Solve/Investigate the Problem
Create an equation based on the
way the problem is written (order of stipulations) and a spreadsheet to support/solve
the problem.
Investigation/Exploration
of the Problem
Equation where n=number
n+129= 2(129n)
n+129=2582n
3n=129
n=43
Double Trouble





N

N+129

129N

2(129N)

50

179

79

158

49

178

80

160

48

177

81

162

47

176

82

164

46

175

83

166

45

174

84

168

44

173

85

170

43

172

86

172

Extensions of the Problem
The
problem can be further explored by writing the equation as follows:
n+129=2(n129)
n+129=2n258
387=n
387+129=2(387129)
516=2(258)
516=516
Discussion and examination of the order of
stipulations will eliminate this equation as a possibility (add to and
subtract from).
Author & Contact
Susan Kelly
mailto:skelly@rockdale.k12.ga.us
Link(s) to resources, references, lesson plans, and/or other
materials
Link 1
Link 2
