Number SentencesOnline version Creating number sentences to match word problems. by Olivia Arnett 1 Does this word problem ask us to add or subtract? a add b subtract c both d neither 2 Another word for 'number sentence' is... a number string b math c equation d talking Explanation 1 The key phrase "in all" tells us that we should use addition. 2 The key phrase "in all" tells us that we should use addition.