Make a decimal amount larger or smaller
Scale a measured amount exactly while keeping its original unit.
Explore this lesson →12 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- Multiplying by ten makes ten copies; dividing by ten keeps one of ten equal shares.
- The original and changed measurements use the same unit.
- Trailing fractional zeros do not change an amount, but scaling does.
Something to notice
Ask the learner to choose a fresh decimal amount and explain tenfold scaling with a strip or place chart. Ask why an added trailing decimal zero is different. Listen for the fixed unit, original quantity, factor count and zero placeholders.
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 5 · 5.NBT · 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.