This task is from Tools 4 NC Teachers. Students examine a claim about place value and multiplying by 10 and provide reasoning about whether or not the statement is true. This is remixable.

Task Preview

In class Veronica told her teacher that when you multiply a number by 10, you just always add 0 to the end of the number.  Think about her statement (conjecture), then answer the following questions.

When does Veronica’s statement (conjecture) work?

When doesn’t Veronica’s statement (conjecture) work?

Is the opposite true?  When you divide a number by 10, can you just remove a 0 from the end of the number?  When does that work? When doesn’t that work?

Rewrite Veronica’s statement (conjecture) so that it is true for ALL numbers.  Write a statement (conjecture) about what happens when you divide a number by 10. 

Rewrite your statement (conjecture) again so that it applies to other multiples of 10.