# 4.MD.3. Apply the area and perimeter formulas for rectangles in real world and mathematical problems.

 ITP Area View full screen in your browser. This ITP allows you to colour in cells on a grid, a full cell or half a cell, or to place a circular counter into a cell. There are three choices of grid size: 5 by 5, 10 by 10 or 20 by 20. The grid can be hidden or replaced by a pin board around the points of which rubber bands can be stretched. The making of different shapes and patterns can support the teaching of number, shape and space and problem solving, for example, to identify the positions of counters in a given sequence or to find the number of nets of an open cube. The flexibility offered by the ITP allows it to be used to support a variety of teaching and learning contexts in mathematics. This resource is freely available to download from the archived Primary Framework site. ITP isogrid View full screen in your browser.  This ITP allows you colour the equilateral triangles set out on an isometric grid. The grid can be hidden or become an isometric pin board. An ‘elastic band’ can be stretched around the pins to create outlines. One of three different rhombuses can be selected and dragged to different positions on the grid. These three rhombuses can be locked together to form the isometric view of a cube. Skeleton outlines of rows and columns of cubes can be formed this way and by colouring in two adjacent triangles, coloured faces can be created. The ITP can be used to explore properties of shapes and space. The making of different shapes and patterns can support the teaching of number and problem solving, for example, to explore the interior and exterior angle and symmetry of polygons made up of equilateral triangles and to identify the patterns in triangle numbers. The flexibility offered by the ITP allows it to be used to support a variety of teaching and learning contexts in mathematics. It can be used in conjunction with the Area ITP to look at the nets of 3-D shapes represented on the isometric grid. This resource is freely available to download from the archived Primary Framework site. For more shape and space resources click here.