In contrast to the task on which it was based, students must provide the picture in this case, giving the alignment with 5.NF.B.6. This task was adapted from in order to provide a context relevant for the Chicago audience for this work. Multiplication as scaling (5.NF.5) provides important experience viewing one quantity as a multiple of another, laying the foundation for ratios. One goal of this work was to highlight different aspects of the ratio and proportion progression. This task was developed with the assistance of a group of teachers from Washington and Illinois in connection with an SBAC digital library project. Much more information about these buildings and others can be found here.

Interestingly, both the Eiffel Tower and the Willis Tower were the tallest building in the world at the time of their construction. The Burj Khalifa is currently the world's tallest building. For a follow-up question, the teacher may wish to ask students how many times taller the Burj Khalifa is than the Willis Tower: the pictures in part (b) will help with this but students will need to break both the Willis Tower and the Burj Khalifa into equal sized parts of the Eiffel Tower (tenths) to answer the question. Students can compare these two heights either by reasoning about the size of the two given scalar multiples or using pictures as in part (b). More work is necessary, however, to compare the Willis Tower to the Burj Khalifa because these heights are only given in reference to the height of the Eiffel Tower. Students will recognize (5.NF.B.5) that the Burj Khalifa is taller than the Eiffel tower and that the Eiffel Tower is shorter than the Willis Tower using the size of the given multiplicative scalars. The goal of this task is to compare three quantities using the notion of multiplication as scaling.

Compare heights