The middle ribbon clue
Compare two lengths by using a third object as a reference.
Explore this lesson →6 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- You can compare A with B, and then compare B with C.
- If A is longer than B and B is longer than C, A must be longer than C.
- Sometimes two facts are not enough. If A and C are both longer than B, either could be longer than the other.
Try it. Change it. Explain it.
Open the lesson to use its pictures and controls. In How it works, connect the picture to the idea. In Play & discover, change the quantities and notice what stays the same. In Your turn, answer questions and use the explanation to check your reasoning.
You can ask for help, draw on the thinking pad, or listen to the question and answer options. Progress distinguishes independent work from work completed with help.
Let’s try it →Curriculum connection
Grade 1 · 1.MD · US Common Core
This lesson is mapped to these standards. A completed activity is practice evidence, not a claim of mastery. Content is checked against the linked official standards and its mathematical models are tested.