Idiot\'s Guides Basic Math and Pre-Algebra

Chapter 1: Our Number System 9 CHECK POINT Write 10,000 as a power of ten. Write 100,000,000,000 as a power of ten. Write 10^7 ...

10 Part 1: The World of Numbers To write a large number in scientific notation, copy the digits and place a decimal point after ...

Chapter 1: Our Number System 11 Rounding ....................................................................................... ...

12 Part 1: The World of Numbers CHECK POINT Round each number to the specified place. 942 to the nearest hundred 29,348 to the ...

CHAPTER 2 Arithmetic In This Chapter Practice addition with regrouping Learn to look for compat- ible numbers Practice subtract ...

14 Part 1: The World of Numbers fish that are left, but before too long, you grasp subtraction: 8 – 4 = 4. Addition and subtract ...

Chapter 2: Arithmetic 15 When you add 3 + 5, you get 8, a single digit. That could be adding 3 ones and 5 ones to get 8 ones, bu ...

16 Part 1: The World of Numbers Our 15 tens can be broken up into one group of 10 tens and one group of 5 tens. The group of 10 ...

Chapter 2: Arithmetic 17 Adding Longer Columns Addition is officially a binary operation. That means that it works with two numb ...

18 Part 1: The World of Numbers Keep the chain of additions going, column by column, and don’t be alarmed when the thousands col ...

Chapter 2: Arithmetic 19 DEFINITION The associative property is a property of addition or multiplication that says that when you ...

20 Part 1: The World of Numbers CHECK POINT Use compatible numbers to help you complete each addition problem. 18 + 32 + 97 91 ...

Chapter 2: Arithmetic 21 Subtraction Subtraction is often thought of as a separate operation, but it’s really a sort of backward ...

22 Part 1: The World of Numbers You can use the add-back method of subtraction whenever it seems convenient, even if you’re not ...

Chapter 2: Arithmetic 23 CHECK POINT Subtract by adding back. 100 – 62 250 – 183 500 – 29 19. 400 – 285 20. 850 – 319 Multipli ...

24 Part 1: The World of Numbers Basic Multiplication Facts ×123456789 1 123456789 2 2 4 6 8 10 12 14 16 18 (^3369121518212427) ( ...

Chapter 2: Arithmetic 25 1 hundred that’s been waiting and you’ll have 11 hundreds. Of course, 11 hundreds form 1 group of 10 hu ...

26 Part 1: The World of Numbers Next, because you know that our next multiplication is by 3 tens and will add a zero, you’ll put ...

Chapter 2: Arithmetic 27 WORLDLY WISDOM There’s a method of multiplication that never requires you to multiply more than one dig ...

28 Part 1: The World of Numbers Division Division is the inverse, or opposite, of multiplication. If multiplication answers ques ...