Grid paper: building, routes and area by cells
Build a rectangle on a grid, measure the length of a route, find the area of a figure by cells and estimate a round shape with a palette.
- Russia: grade 5
Guide
Squared paper is the favourite tool of Russian primary and middle school. The side of a cell is the unit of length and a cell is the unit of area. In Grades 5-6 children build rectangles and squares with given sides, measure routes with turns and find an area by splitting a figure into rectangles or completing it to a rectangle.
A "palette" (палетка) is a transparent square grid for estimating the area of an irregular figure: count whole cells and count the part cells as half. The answer is approximate (≈). Pick's formula appears in Grade 8 as an extra and is not required.
Common slips: mixing up the length of a route with the number of segments; forgetting to subtract the added part; counting whole cells only; using the perimeter for the area.