Comparing and combining paired bars

Last lesson, you read a bar graph using its scale. Some bar graphs show two kinds of things, like cats and dogs. A legend tells us which colour is which. Today, we use the legend to find totals, and then we compare them. The bar graph shows the number of storybooks and comics borrowed from the class library on three days. How many more storybooks than comics were borrowed altogether? The legend shows that blue bars are storybooks and pink bars are comics. Altogether means all three days. So first, we find the total of each kind. Start with the blue bars. On Monday, the top of the bar is level with 20. On Tuesday, the blue bar shows 10. On Wednesday, it shows 30. 20 plus 10 is 30. 30 plus 30 is 60. Now the pink bars. On Monday, the pink bar shows 25. On Tuesday, it shows 15. On Wednesday, it shows 5. 25 plus 15 is 40. 40 plus 5 is 45. 60 is more than 45, so we subtract to find how many more. 60 minus 45 is 15. So 15 more storybooks than comics were borrowed altogether. On Monday and Tuesday, the pink bars are taller, but altogether more storybooks were borrowed.

The bar graph shows the number of apples and pears sold at three stalls at a school fun fair. How many pieces of fruit did Stall B sell altogether? Try it first. Pause if you like. Blue bars are apples and pink bars are pears. At Stall B, the blue bar shows 15 and the pink bar shows 25. 15 plus 25 is 40. Stall B sold 40 pieces of fruit altogether.

The bar graph shows the number of paper stars and paper boats made by three teams. How many more items did Team A make than Team C? Try it first. Pause if you like. Blue bars are paper stars and pink bars are paper boats. We compare the total for Team A with the total for Team C. Team A made 25 stars and 20 boats. 25 plus 20 is 45. Team C made 30 stars and 5 boats. 30 plus 5 is 35. 45 minus 35 is 10. Team A made 10 more items than Team C. Read the legend and compare a complete total with a complete total.