Number Sentence
a + b = c
1 + 2 = 3
An equation
http://www.education.com/question/number-sentence/
http://www.mathatube.com/algebra-number-sentence.html
http://www.aaaknow.com/g4_18cx1.htm
http://www.onlinemathlearning.com/number-sentence.html
http://www.onlinemathlearning.com/number-sentence-words.html