# 1.MD.A.1

Order three objects by length; compare the lengths of two objects indirectly by using a third object.

## Summary:

This standard emphasizes a student’s ability to sort and order three objects according to their lengths. For example, a student might compare the height of a desk on one side of a room with the height of a table on the other side of the room by finding a rod and comparing each of the first two heights to the length of the rod.

## Understanding the Standard:

• Students need practice with comparing three objects according to their lengths. The objects that are being compared should be comparable to one another in types of measurement - weight or volume, for example (e.g., three pieces of the same type of string or rope that is cut into three differing lengths). Emphasis on comparison vocabulary is imperative.
• Students can compare the height of a desk on one side of the classroom to the height of a table on the other side of the classroom by finding a rod and comparing each of the first two heights to the length of the rod.
• Teachers should engage students in comparing objects or things familiar to the students in the classroom so that the lessons are more concrete for young children

## Questions to Focus Instruction:

• Can students compare lengths of different types of objects (e.g., a yardstick, a table, and a book)?
• Can students find an object whose length is between two given lengths? If length A is bigger than length B and length B is bigger than length C, do students correctly assume that length A is bigger than length C without directly comparing A and B?
• Can students appropriately use comparison words such as long, longer, and longest? Small, smaller, and smallest? Short, shorter, and shortest?
• Which manipulatives and other technologies might I make available for students to explore in using as a comparison object/tool for direct, hands-on exploration of measuring the lengths of objects?

## Skills

Prior to: Students can make comparisons between two and three objects by directly comparing objects side by side, lined up, etc. They can use comparison words such as long, longer, longest; short, shorter, shortest; tall, taller, tallest; and small, smaller, smallest. They can use positional words to communicate the position of objects. Students are able to make comparisons of length by DIRECTLY comparing objects (side by side, lined up, etc.) See K.MD.A.2.