--- title: Adding all the rows — a lesson of Mova's school · trees and pragmatics description: «Adding all the rows», a lesson of the lessons course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: When rows grow by the same number, pair the first row with the last, the second with the one before the last, and so on: every pair has the same sum. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/lessons/177-sum-of-rows/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Lessons](https://md.mova.elamur.ai/free/en/corpora/school/lessons/) / Adding all the rows # Adding all the rows Lesson 177 of the lessons course of Mova's primary school: 4 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). - [0](https://md.mova.elamur.ai/free/en/corpora/school/lessons/177-sum-of-rows/0/) — When rows grow by the same number, pair the first row with the last, the second with the one before the last, and so on: every pair has the same sum. - [1](https://md.mova.elamur.ai/free/en/corpora/school/lessons/177-sum-of-rows/1/) — The total is (first + last) × number of rows / 2, and the last row is first + (rows - 1) × step. - [2](https://md.mova.elamur.ai/free/en/corpora/school/lessons/177-sum-of-rows/2/) — 6 rows: 5, 7, 9, 11, 13, 15 seats. - [3](https://md.mova.elamur.ai/free/en/corpora/school/lessons/177-sum-of-rows/3/) — First + last = 20, 20 × 6 / 2 = 60 seats. - ← previous: [Which row? Steps that grow by the same number](https://md.mova.elamur.ai/free/en/corpora/school/lessons/176-which-row/) - next →: [Days of the week after many days](https://md.mova.elamur.ai/free/en/corpora/school/lessons/178-days-of-the-week/) - ↑ back to [Lessons](https://md.mova.elamur.ai/free/en/corpora/school/lessons/)