Intro to decimals for grades 4-5.
Learn decimal numbers
solidly from the start.
parents teachers Complete curriculum supplemental
header line

You are here: HomeBlue Series → Decimals 1

Math Mammoth Decimals 1 Workbook

Math Mammoth Decimals 1 is a self-teaching worktext about decimal numbers. It suits best 4th and 5th grade in normal teaching.

This ebook deals with decimal numbers that have tenths and hundredths - numbers with maximum of two decimal digits. The idea here is to lay a strong conceptual foundation in students' minds so that they can do the basic operations with these decimals mentally.

Of the operations, the book deals with addition, subtraction, and multiplying by a whole number, with strong emphasis on mental calculations. Multiplying a decimal by a decimal is not presented in this book, and division is not dealt with at all.

Why is that? The idea is to lay such a solid foundation that the student grasps the concepts and does not succumb to rote memorization of calculation rules without understanding.

The two operations not dealt with in the book are multiplying a decimal by a decimal, and decimal division. These two operations are the ones that students often only memorize how to do them - and sadly also often forget a few years afterwards.

Decimals 1 ebook uses number lines, fraction models, and place value charts - and makes the student draw them too - to teach the concepts of tenths and hundredths. Other topics covered are comparing decimals, adding and subtracting decimals both mentally and in columns, multiplying a decimal by a whole number both mentally and in columns, rounding, estimating, and money problems.

If children cannot add decimals mentally, they may rely too much on adding in columns or on the calculator, without really understanding decimals. That is why in my book the student is often made to compare decimal operations with corresponding fraction operations.

A common error is to add 0.4 + 0.8 = 0.12 etc.: children consider the decimal part of a number as a 'separate whole number' and try to apply whole number arithmetic within the decimal part. Emphasizing the equivalency to fractions and how fractions are added should help.

The student should think of 0.4 as "four tenths" and 0.8 as "eight tenths", and then realize how twelve tenths is more than one, hence 0.4 + 0.8 = 1.2.

The book also emphasizes how to add decimals of different "length". When adding one number with one decimal digit and another with two, for example 0.4 + 0.08, you will 'tag' a zero to the end of 0.4 so both addends will have same amount of decimal digits. This is the exact same thing as making the corresponding fractions to have the same denominator (denominators 10 and 100 are made to be 100 and 100).

From a homeschooling parent who has used Decimals 1 with a 5th grader:

My 5th grader and I worked through the decimals book. It actually helped me to understand decimals a lot better also. We were both amazed at how easy they are to work with once you understand the concepts behind them.

I love the books. They include a lot of thinking and reasoning skills that our other math program did not include. They also present things in a simple clear manner. No more tears when it comes to decimals!!!

Michele Cutlip

Better Yet - Package Deals!
Blue Series package - $70 (download) or $75 (CD)
Blue Series for grades 1-3 - $40 (download)
Golden/Green Series package - $65 (download) or $70 (CD)
Light Blue Series package - $99 (download) or $104 (CD)
Blue/Golden/Green Series package - $110 (download) or $115 (CD)
All Inclusive package - $150 (download) or $155 (CD)

Learn more about the package deals!

*BONUS*: Buy any package listed above, and get the fully upgraded Soft-Pak software with more features and options for FREE (includes 4 math, 1 language arts, 2 testing programs).
*BONUS* - SOFT-PAK MATH SOFTWARE

I bet you'd have to agree: this is a steal! You can get Soft-Pak math programs (list price $24.95) for just a small $3.50 s&h fee - just by ordering ANY of my books at Kagi or CurrClick!

* Math Maker, for printable math activities with answer keys
* Math Master, for on screen practice of various math topics
* Math User, for answering the 900 multi-level word problems
* True/False Math Challenger for mastering facts 1-12


NOTE: if you purchase one of the package deals at Kagi store, you will get Soft-Pak in the download or included on the CD for FREE.

Soft-Pak may also be purchased at great 75% discount without a Math Mammoth purchase - click here for details.

How and where to order

You can buy Math Mammoth books at:

  • Kagi store - all of the downloads and CDs. I maintain five different order pages at Kagi:

    Kagi accepts all major credit cards, Paypal (USD), checks, cash, money orders, purchase orders, wire transfers, and even cash. Read more about the payment methods here. Please see Kagi Shopper Help for any other questions about the ordering process.

    After completing the order at Kagi, you will see the download links on the receipt page. You will also receive an email with download links for each book you bought, or for a zip file for the packages. You click on the links and download the books to your computer's hard drive.

    In case of any problems with the download, you can always email me, and I can email the books to you directly. My contact info will be in the email you receive.


     
  • CurrClick.com carries all Blue, Golden, and Lightblue series books as downloads. They accept credit cards and Paypal. You will be able to download the products immediately upon the purchase, and also return to your account at CurrClick to redownload.
  • The Old Schoolhouse Store carries the Blue Series books as downloads. Credit cards, Paypal.
  • Lulu has printed copies for the Blue, Golden, and Light Blue series books. For each book at MathMammoth.com, you can find a link to the printed copy sold at Lulu on each individual book's page (right sidebar).
  • Winterpromise sells printed copies and CDs for the Light Blue series grades 1-4.

By purchasing any of the books, permission IS granted for the teacher (or parent) to reproduce this material to be used with his/her students in a teaching situation; not for commercial resale. However, you are not permitted to share the material with another teacher.

In other words, you are permitted to make copies for the students/children you are teaching, but not for other teachers' usage.

  • Navigate by topic
  • Navigate by grade

The books listed below are from the Blue Series (worktexts by topic) and the Green Series (worksheet collections by topic). If you are looking for full curriculum by grade, or for workbooks/worksheets by grade level, please click on the "Navigate by grade" tab.

Addition & Subtraction

Addition 1 worktext (grade 1)
Subtraction 1 worktext (grade 1)
Add & Subtract 2-A worktext (grades 1-2)
Add & Subtract 2-B worktext (grade 2)
Add & Subtract 3 worktext (grades 2-3)
Add & Subtract 4 worktext (grades 3-4)

Place Value

Place Value 1 worktext (grade 1)
Place Value 2 worktext (grade 2)
Place Value 3 worktext (grade 3)
Place Value 4 worktext (grade 4)

Multiplication & Division

Multiplication 1 worktext (grade 3)
Division 1 worktext (grade 3)
Multiplication 2 worktext (grade 4)
Division 2 worktext (grade 4)
Multiplication Division 3 worktext (grade 5)
Multiplication & Division worksheets (grades 3-6)
Numbers & Operations worksheets (grades 3-6)

Clock and Money

Clock worktext (grades 1-3)
U.S. Money worktext (grades 1-3)
Canadian Money worktext (grades 1-3)
European Money worktext (grades 1-3)

Measuring

Measuring 1 worktext (grades 1-3)
Measuring 2 worktext (grades 4-5)
Metric Measuring worktext (grades 1-4)
Measuring worksheets (grades 3-6)

Fractions

Introduction to Fractions worktext (grades 2-4)
Fractions 1 worktext (grades 5-6)
Fractions 2 worktext (grades 5-6)
Fractions worksheets (grades 3-6)

Decimals

Decimals 1 worktext (grades 4-5)
Decimals 2 worktext (grades 5-6)
Decimals worksheets (grades 3-6)

Geometry

Early Geometry worktext (grades 1-3)
Geometry 1 worktext (grades 4-5)
Geometry worksheets (grades 3-7)

Other topics

Integers worksheets (grades 5-6)
Ratio, Proportion & Percent worksheets (grades 5-7)
Statistics worksheets (grades 4-7)

Make It Real Learning

States by the Numbers series (grades 3-6)
Arithmetic I (grades 3-6)
Fractions, Percents, and Decimals I (grades 4-8)
Fractions, Percents, and Decimals II (grades 4-8)
Sets, Probability, and Statistics I (grades 6-10)
Linear Functions I (grades 9, 11)
Linear Functions II (grade 11)
Quadratic Functions I (grades 9, 11)
Exponential & Logarithmic Functions I (grades 11-12)
Periodic & Piecewise Functions I (grades 11-12)
Polynomial, Power, Logistic & Rational Functions I (grades 11-12)
Calculus I (grade 12)

Math Teaching Emails


This is a little "virtual" email course. You will receive:

A package of 280 free worksheets and sample pages; 7 math teaching articles on various topics ranging from coherent curriculum to fractions; 2 emails discussing the books; Homeschool Math newsletter (see archives).

Note: You will FIRST get an email that asks you to confirm your email address. PLEASE check also your SPAM/JUNK folder for this confirmation email.

Math Mammoth Tour


Confused about the different options? Take a 7-day virtual email tour around Math Mammoth! You'll receive:

A package of 280 free worksheets and sample pages; 7 individual emails on 7 subsequent days that answer the most commonly asked questions, including "What is the difference between all these different-colored series?" Homeschool Math Newsletter (see archives).

This way, you'll have time to digest the information over one week, plus an opportunity to ask me personally which book would be right for your child or students.

Note: You will FIRST get an email that asks you to confirm your email address. PLEASE check also your SPAM/JUNK folder for this confirmation email.

CurrClick