Unit 2 Review: Applications with Decimals

Lesson Goal

Bring the ten Unit 2 lessons together, check which tools hold, and find the ones that need a second read before Unit 3 starts.

This is a diagnostic, not a test. Every question's hint names the lesson to reopen, so a wrong answer is a pointer and not a grade.

How to Use It

Read the review once, then do the questions. For every miss, open the lesson the hint names and read just the section it points to, then come back.

If the student misses two questions from the same moment of the habit (before, during or after), that moment is the one to re-teach.

Where Students Get Stuck

🚨 Moving only one decimal point when dividing, and rounding money down when sharing a cost. The first changes the problem and the second leaves the bill unpaid.

Skipping the last step. A student who gets an answer and stops should be asked what it was supposed to be about, before looking at the key.

Key Vocabulary

Estimate

A quick, rounded answer that shows roughly where the real one should land.

Decimal places

The digits to the right of the decimal point. A product has as many as its two factors have together.

Power of Ten

A number like 10, 100 or 1,000 made by multiplying 10 by itself.

Scientific notation

A way to write a number as one digit in front of the point times a power of ten.

Divisor

The number you divide by.

Quotient

The answer to a division problem.

Prefix

The part at the front of a metric unit, like kilo or milli, that tells you the place value.

Reasonable

Close enough to your estimate that the answer is probably right.