PDF download $5.65
Printed copy $8.40, b&w
Math Mammoth Add & Subtract 2-B is a continuation to the book Math Mammoth Add & Subtract 2-A. The goal of this book is to study addition and subtraction within 0-100, both mentally and in columns, especially concentrating on regrouping in addition (carrying) and in subtraction (borrowing).
Mental math is important because it builds number sense. This book includes many lessons that practice mental math. For example, the child practices adding and subtracting two-digit numbers when one of the numbers is a whole ten (problems such as 30 + 14, or 66 − 20).
Also studied are problems such as 36 + 8 or 45 + 9. These problems use the idea of going over ten as in problems 6 + 8 and 5 + 9. The child knows that 6 + 8 fills the first ten and is four more than the ten. He/she will learn to use that fact when adding 36 + 8. The sum 36 + 8 fills the next whole ten (40), and is four more than that, or 44.
Simultaneously with this, the child learns adding two-digit numbers in columns, and regrouping with tens, or "carrying," which is illustrated and explained in detail with the help of visual models. These visual models take the place of base-ten blocks or other manipulatives. You are welcome to use manipulatives to get the idea across, if you prefer. The main concept to understand is that 10 ones are regrouped to form a new ten, and this new ten is written using a little "1" in the tens column.
The next lessons teach subtracting in columns. First we only deal with the easy problems where you don't need to regroup (borrow). Then the following lessons practice in detail the process of regrouping or borrowing. You can use either term with your child, or even choose not to use either if you feel it is confusing. You can alternatively use the phrase "breaking a ten into ten ones."
First, the lesson Regrouping practices breaking down a ten into ten ones because we cannot subtract from the ones. It is crucial that the child understands what happens here. Otherwise, he/she might end up only memorizing the procedure, and will probably at some point misremember how it was done. That is why this lesson deals with the regrouping process in detail with plenty of visual exercises.
If you notice that the child does not understand the concept of regrouping, he/she may need more practice with concrete manipulatives or visual exercises before proceeding.
After learning regrouping, we practice mental subtraction in three separate lessons. One of them expounds on several methods for mental subtracting. Another is about Euclid's game—a fun game that also practices subtraction of two-digit numbers.
The video below shows a similar idea as to what is in the book about regrouping (borrowing).
Better Yet - Bundle Deals!
Blue Series - $105 (download) or $110 (CD)
Blue Series for grades 1-3 - $42 (download)
Blue Series for grades 4-6 - $63 (download)
Light Blue Series - $150 (download) or $155 (CD)
Light Blue Series for grades 1-3 - $75 (download)
Light Blue Series for grades 4-6 - $75 (download)
Golden/Green Series - $65 (download) or $70 (CD)
All Inclusive - $211 (download) or $216 (CD)
"Everything" Bundle - $276 (download only)
Learn more about these Math Mammoth bundles!
*BONUS*: Buy any bundle 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).
Maria's Math News
This is my newsletter that comes out about once or twice a month. Peek at the previous volumes here.
You will receive:An initial email to download a GIFT of over 350 free worksheets and sample pages from my books; Maria's Math News: my newsletter filled with math teaching resources, news, downloads, humor, and giveaways. The content is equally good for all of us who teach math.
Math Mammoth Tour
Confused about the different options? Take a 7-day virtual email tour around Math Mammoth! You'll receive:An initial email to download your GIFT of over 350 free worksheets and sample pages from my books; 6 other emails on 6 subsequent days that describe the different series of Math Mammoth products, answering the most commonly asked questions, including "What is the difference between all these different-colored series?"
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.
"Mini" Math Teaching Course
This is a little "virtual" email course. You will receive:An initial email to download your GIFT of over 350 free worksheets and sample pages from my books; 7 articles on important topics on mathematics education, including: multiplication tables, fractions, how to help a student who is behind, and the value of mistakes; 1 email about Math Mammoth books.
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.
© 2006-2014 MathMammoth.com