Starter activity in PowerPoint involving rounding to significant figures. There are 20 different questions of varying degrees of difficulty. All question slides have animated answers. The activity also has a worksheet linked to the Bingo questions, with answers on separate slide. How to play Get students to draw a 3x3 grid in their books, then select 9 numbers between 1 and 20 from the larger grid (NO REPEATS). Select a student to answer a question (the answer is animated in when you next interact with the board) if they get it right, they get to cross off one of their numbers from their grid (any student with the same number can also cross off that number). Cross off all 9 and BINGO…they win. What do they win, you decide (I hand out pens sometimes or get the rest of the class to give a round of applause). I’ve made it sound more complicated than it really is. This activity is great as a starter or as a plenary as well as testing prior knowledge. Hope you like.