Place Value and Decimals

The Common Core State Standards covered in Unit 3 are:

  • Demonstrate an understanding that in a multi-digit number, each digit is 1/10 of what it represents in the place to its left.
  • Explains patterns in the number of zeros in the product when multiplying by powers of 10, and in the placement of the decimal point when multiplying or dividing by powers of 10.
  • Writes decimals to thousandths with base 10 numerals, words and in expanded form. An example of expanded form is as follows:

                    347.392 = 3 100 + 4 10 + 7 1 + 3 (1/10) + 9   (1/100) + 2 (1/1000)
  • Compare pairs of decimals to thousandths, based on an understanding of what the digit in each place value represents.
  •  Uses >, =, and < symbols to record comparisons of two decimals to thousandths.
  • Round decimals to the nearest one, tenth, and hundredth.
  • Divides a 3-digit whole number by a 2-digit whole number using strategies based on place value, the properites of operations, or the relationship between multiplication and division. 
  • Add and subtract decimals to hundredths, using concrete models or drawings and strategies based on place value and properties of operations, and the relationship between addition and subtraction. 
  • Add and subract fractions with unlike denominators, including mixed fractions. 
  • Convert among different sized standard measurement units within a given measurement system.

Cut-Eye weighs 50 pounds more than Praiseworthy.

Together, they weigh 130 pounds.

What does Praiseworthy weigh?

Jack has $21 more than Quartz Jackson and $48 more than Pitch-pine Billy.

Altogether they have $168.

How much money does Jack have?

Jack is twice as old as Constance who is 5 years older than Pearley.

Sarah is 6 years older than the sum of Constance and Jack's ages.

If the sum of the ages of all four people is 78,

how old is Sarah?

Four consecutive numbers add up to 1850.

What is the smallest number?

  Try These!


It takes Isaac 10 minutes to ride his bike down the hill to school and 20 minutes to ride up the hill from school.

He attends school Monday through Friday. How many minutes does he spend biking to and from school in two weeks?

It took Davina 45 minutes to clean her room

How many seconds did it take her?

One family of scrub jays inhabits about 25 acres of land.
No other scrub jay families live within the area.

How many acres of land do 24 families of scrub jays need?

The 2001 record for balancing drinking glasses was 75 glasses.

If the capacity of each glass was 20 fluid milliliters, how many total fluid milliliters could all of the glasses contain?

A nursery sells plants in flats.

There are 6 plants in each tray.

Each flat has 6 trays.

The nursery sold 18 flats on Saturday and 21 flats on Sunday.

How many plants did the nursery sell in all?

Time for Some Links!

Introduction to Decimals-Start here!
Reading and Writing Decimals
Comparing Decimals
Ordering Decimals

Decimal Place Values
Place Value from Khan Academy
Place Value Chart-Whole Numbers and Decimals
What Decimal Number is Illustrated in the Model?
Place Value Word Quiz
Compare Decimal Numbers Using a Model
Put the Decimal Numbers in Order
Write the Decimal Number From the Words
Match the Decimal Number to the Word
What is the Decimal Number? practice expanded form
Convert Fractions to Decimals Using Expanded Form
Compare Fractions and Decimals on a Number Line
Convert Fractions to Decimals
Put Fractions and Decimals in Order

Rounding Decimals to the Nearest Teneth-Khan Academy Video
Practice Rounding Decimals-Khan Academy
Rounding Decimals to the Nearest Whole Number-IXL Math
Rounding Decimals to 10ths, 100ths, and 1000ths-IXL Math
Rounding Decimals-Make the statement true-IXL Math
Rounding Decimals to the Nearest Tenth-aaamath
Rounding Decimals to the Nearest Hundredth-aaamath
Rounding Decimals to All Place Values-aaamath

Ships and Boats
Decimal Soccer
Throw the Darts- great estimation game
Death to Decimals
Place Value Pirates
Ordering Decimals
Place Value Word Search
Decimals of the Caribbean
Decimal Squares Blackjack
Decimal/Fractions Matching
Decimal Place Value Football
Math Baseball-Decimal Rounding
Fractions, Decimals and Percents Jeopardy
Convert Fractions and Decimals to Percents-Millionaire Style

How to Add and Subtract Decimals
Adding Decimals-Khan Academy Video
Subtracting Decimals-Khan Academy Video
Estimating Sums and Differences-IXL Math
Online Practice of Adding Decimals-IXL Math
Online Practice of Subtracting Decimals-IXL Math
Make a Sum or a Difference with Decimals-IXL Math
Addition and Subtraction Decimal Word Problems-IXL Math
Online Practice-Mixed Adding and Subtracting Decimals-IXL Math
Comparisons of Addition and Subtraction Decimal Problems-IXL Math
Complete the Decimal Equation-Adding and Subtracting Decimals-IXL Math
Adding Decimals Using
Subtracting Decimals Using
Online Practice of Adding
Online Practice of Subtracting

Pirates Game
Powers of 10 Flash Cards
Matching Game-has some decimals
Multiply by Powers of 10 using Exponents
How to Multiply by Powers of 10-Explained
Online Practice for Multiplying by Powers of 10
Multiplying by Powers of 10 Using Exponents
Multiplying by Powers of 10 Explained -Video Lesson
Word Problem Practice for Multiplying by Powers of 10
Divide by Powers of 10-IXL Math
How to Divide by Powers of 10-VIDEO
Divide Decimals by Powers of 10-Khan Academy
Online Practice for Dividing by Powers of 10
How to Multiply and Divide by Powers of 10
Multiplying and Dividing by Powers of 10-Khan Academy
Multiply and Divide by Powers of 10-online practice
Excellent Online Practice for Multiplying and Dividing by Powers of 10

Introduction to the Metric System
Length and Distance Quiz
Compare Metric
Practice the Metric
Convert Metric Units of Length-IXL Math
Convert Many Units in the Build a Shed Game
Explore Metric Lengths-Information and Practice
Practice Converting Metric Units-Matching Game
Convert Centimeters and Meters-Rule Slide Game
Compare and Convert Metric Units-Online Practice

Metric Weight Unit Matching
Convert Units of Weight-Khan Academy
Units of Mass-English and Metric Practice
Metric Weight Video and Online Activities
Convert Metric Units of
Compare Metric Units of
Metric Weight-Explanation and Practice Problems
Compare and Convert Metric Units of Weight-IXLMath

Compare Metric Capacities
Compare Metric Capacities
Convert Metric Units of
Metric Capacity-Instruction and Online Practice Problems
Compare and Convert Metric Units of Capacity-IXL Math
Matching Capacities
Can You Spot the Mistake?
Comparing Capacities-fact sheet + quiz
VIDEO: Metric Units of Capacity-Khan Academy

Time to Exercise the Brain~

Daily Sudoku for Kids Brain Benders Play Rags to Riches
Prime Factorization Online Game
Uncross the Lines
Online Mankala
Who Wants to Win $1,000,000.00? Algebraic Expressions Hundredaire Game
Family Math Challenges
 What's the Best Way to get Paid?  Mystery Math Probability with Spinners

to the math sites that we love!


Great Help for Most Place Value Need help? Ask Dr. Math
Practice rounding with online flashcards 62 Math Games-5th grade level
Online Flashcards-all operations Tons of chances for practice-worksheets
Challenging Math Problems
A+ Math Games
Math Mania Challenges
Illustrated Math Dictionary
Mystery Math-How do they do that? Order of Operations
Cool Math-Interactive Activities
Math Baseball
Problems of the Week
Tesselations-Math is Fun!
The Fruit Game Math Playground