title: Training a neural network to add
body: <p>I need to train a network to multiply or add 2 inputs, but it doesn't seem to approximate well for all points after 20000
  iterations. More specifically, I train it on the whole dataset and it approximates well for the last points, but it seems
  like it isn't getting any better for the first endpoints. I normalize the data so that it is between -0.8 and 0.8. The
  network itself consists of 2 inputs 3 hidden neurons and 1 output neuron. I also set the network's learning rate to 0.25,
  and use as a learning function tanh(x).</p>
  
  <p>It approximates really well for points that are trained last in the dataset, but for the first points it seems like it
  can't approximate well. I wonder what it is, that isn't helping it adjust well, whether it is the topology I am using, or
  something else?</p>
  
  <p>Also how many neurons are appropriate in the hidden layer for this network?</p>