Error While Using The Precision Metric For MNIST Digit Classification

I am trying to achieve a high Precision score on the MNIST dataset using Tensorflow and Keras. My code is working if I set the metric to accuracy but when I set it to precision, it

Solution 1:

Precision, is a metric for binary classification. It computes true_positives and false_positives then simply divides true_positives by the sum of true_positives and false_positives.

But Accuracy metric can be used for multi-class classification like MNIST, because it calculates how often predictions equal labels.