The only book your child needs for basic subtraction proficiencyThis book takes a child who already has proficiency in basic addition to proficiency in basic subtraction as well. This corresponds roughly to the arithmetic taught – but not necessarily learned – in the second semester of first grade in most U.S. public schools. In addition to the workbook, the child may need an adult to read the brief instructions on each page, and perhaps to help explain concepts once or twice over the course of the book.Note that throughout this book the number being subtracted is never larger than the number being subtracted from, so negative numbers are not introduced, although the number 0 is used.Prior to starting this book, the child should know how to count to 100 and be able to write double digit numbers, and should be reasonably proficient at adding two single digit numbers, and perhaps a single digit number to a number in the teens, on paper. Children who are not yet proficient at that level of addition would be better off starting with Grade 1 Addition (Kumon Math Workbooks) .This book consists of 43 double pages of problems, with some front matter and an answer key in the back. Each pair of pages has 40-50 problems. The 43 double pages are as follows:1-2 (4 pages) are review of writing two digit numbers by filling in blanks in tables of numbers which go up to 100.3-6 (8 pages) are review of adding two single digit numbers. Page pair 6 also includes half a page of filling in blanks in a table of numbers from 51 to 100.7 (2 pages) introduces subtraction. The first page is on reversing the sequence of numbers from 1 to 10 by filling in parts of sequences from 10 to 1, thus introducing the concept of reducing numbers rather than incrementing them. The second page is on subtracting 1 from numbers from 2 to 11, with a number sequence at the top for reference.8-9 (4 pages) are additional drill on subtracting 1 from numbers between 2 and 11 inclusive.10-17 (16 pages) are on subtracting 1 from numbers between 2 and 14 inclusive (4 pages), on subtracting 2 from numbers between 3 and 15 inclusive (6 pages), and on subtracting 3 from numbers from 4 to 16 inclusive (6 pages). On the first page each time the range of numbers shifts, a number sequence up to the maximum number used is provided for reference.16-23 (12 pages) are on subtracting 4 (6 pages) and subtracting 5 (6 pages) from numbers up to 17 and 18 respectively. The first and last page of each set of 6 pages intersperses subtraction of smaller numbers as well.24-26 (6 pages) are on subtracting numbers up to 6 (2 pages), up to 8 (2 pages), and up to 10 (2 pages) from numbers up to 10.27 (2 pages) are on subtraction of numbers between 1 and 11, inclusive, from numbers between 9 and 11, inclusive. From this point on in the book, the number being subtracted can range up through the number being subtracted from.28-36 (18 pages) are on subtraction of single and double digit numbers from double digit numbers. The maximum number being subtracted from gradually increases from 12 to 20, with 2 pages with each maximum number.37-39 (6 pages) are on subtraction of single and double digit numbers up to 20 from single and double digit numbers up to 20.40-42 (6 pages) are on mixed addition and subtraction operations between three single digit numbers, for example, “9-4 3=”. The first number is occasionally a double digit number if the first operation is subtraction. This provides exercise in mentally tracking an intermediate number while performing the second operation.43 (2 pages) is a review of subtraction of single digit numbers from single and double digit numbers.The book provides a lot of repetition throughout, which makes it suitable as a sole source for learning the material and not just as a supplement to regular schooling. By the end of the book, the child should be proficient in subtracting single digit numbers from larger numbers up to 20.On completion of the book, the child is ready to move on to Grade 2 Addition (Kumon Math Workbooks) , which covers addition of double digit numbers through 99 and introduces the concept of place value for numbers up to four digits in length. In addition, the supplemental books Geometry & Measurement Grade 2 (Kumon Math Workbooks) and Word Problems Grade 2 (Kumon Math Workbooks) may be useful, especially if these books are to be used as a full home school curriculum, rather than just as a supplement to public or private schooling.Unlike many other workbooks, the Kumon workbooks focus on introducing a few concepts in each book and providing enough repetition to ensure the child becomes proficient with the material. My 6 year old, after spending 10 weeks working through this book in her spare time, now has a high degree of proficiency and confidence with basic subtraction as well as basic addition; her intensive work on this book and the previous Grade 1 Addition (Kumon Math Workbooks) raised her mathematics and work habits grades from a mix of Ns (not meeting the standard) and Ps (progressing toward the standard) to all Ms (meeting the standard consistently); that’s a lot better than the school assigned reading specialist did for her in English, where she continued to score mostly Ps with just a few improvements.
