The purpose of this task is for students to reason about base-ten numbers on the number line in a way that will require them to use what they know about place value. Students first represent addition and subtraction on the number line in grade 2 (see 2.MD.6). The standards explicitly call on students to use number lines to solve problems involving fractions and time in third grade (see 3.NF.A and 3.MD.1) and decimals and measurement quantities in 4th grade (see 4.NF.6 and 4.MD.2). The number line is also a very powerful tool for helping students understand place value, and students should be encouraged to use it in third and fourth grade to support their deepening understanding of base-ten numbers. This task provides students such an opportunity, and as such, is aligned to the cluster 4.NBT.A, Generalize place value understanding for multi-digit whole numbers. Aligns with 4.NBT.A.