Ages that grow together: sum and differenceLesson 140 of the lessons course of Mova's primary school: 3 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0).0Each year both children get one year older, so the sum of two ages grows by 2 each year, and the difference never changes.1If two ages add up to 20 and one child is 4 years older, the younger is (20 − 4) ÷ 2 = 8.2If in 3 years the two ages will add up to 26, today they add up to 26 − 3 − 3 = 20.← previousCuts and pieces, posts and gapsnext →Numbers to 1000: adding and taking away in stories↑ back to LessonsThis page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/lessons/140-ages-sum-and-difference/