Recovering missing data and completing bars

Last lesson, you added bars to find a total. All the bars together make one total. Today, we use the information given to find a missing bar, and then we draw it. The bar graph shows the number of seeds planted by three classes. The bar for Class 3B is missing. The three classes planted 75 seeds altogether. How many seeds did Class 3B plant? There is no bar for Class 3B yet. The 75 seeds are for all three classes together. So 75 is not the bar for Class 3B. First, we add the two bars we can see. Class 3A planted 20 seeds. Class 3C planted 30 seeds. 20 plus 30 is 50. The rest of the 75 seeds are for Class 3B. 75 minus 50 is 25. So Class 3B planted 25 seeds. Now we can complete the graph. From 20 to 30 is 10. There are 2 spaces, so each space is 5. 25 is one space above 20. Draw the bar for Class 3B up to 25. Sometimes we are told how many more or fewer instead. We still find the missing number first, and then draw.

The bar graph shows the number of cups of water drunk by three groups on Sports Day. The bar for Group A is missing. The three groups drank 65 cups altogether. How many cups did Group A drink? Try it first. Pause if you like. The 65 cups are for all three groups, so 65 is not the bar for Group A. Group B drank 20 cups and Group C drank 10 cups. 20 plus 10 is 30. 65 minus 30 is 35. So Group A drank 35 cups. Each space is 5, so 35 is one space past 30. Draw the bar for Group A to 35.

The bar graph shows the number of thank-you cards made by three classes. The bar for Class 3C is missing. Class 3C made 25 fewer cards than Class 3A. How many cards did Class 3C make? Try it first. Pause if you like. 25 fewer than Class 3A means we start from the bar for Class 3A. The bar for Class 3A reaches 40. Class 3C made 25 fewer, so we subtract 25. 40 minus 25 is 15. So Class 3C made 15 cards. Each space is 5, so 15 is one space above 10. Draw the bar for Class 3C up to 15. Find the missing count from the information given before completing the graph.