UNIT 1 WHOLE NUMBERS: Addition and Subtraction WHOLE NUMBERS: Addition and Subtraction McGraw-Hill/Irwin© 2007 The McGraw-Hill Companies, Inc. All rights reserved.

1–11–1 Number Line

1–21–2 Symbols

1–31–3 Writing Whole Numbers Using Words

1–41–4 Writing Whole Numbers Using Digits

1–51–5 Aligning Digits by Place Value

1–61–6 Adding Whole Numbers

1–71–7 Add Tens First

1–81–8 Add By Grouping

1–91–9 Checking Addition

1–10 Horizontal Addition

1–11 Horizontal and Vertical Addition

1–12 Use Smaller Groups of Numbers

1–13 Use the Accountant’s Method

1–14 Rounding Numbers

1–15 Estimating Answers in Addition

1–16 Subtraction

1–17 Subtraction

1–18 Checking Subtraction

1–19 Subtracting Horizontally Subtract horizontally. Then find vertical column totals and subtract. Subtract the numbers from left to right. Check by subtracting the total of the subtrahends from the total of the minuends.

1–20 Estimating Answers in Subtraction

1–21 Using Problem-Solving Steps

1–22 Problem-Solving in Business Determine whether there is a debit or credit balance for debits of $160.00, $2,650.50, $65.45, $492.11, and $ and credits of $56.25, $643.90, $85.00, and $ Note that debits are greater than credits, so the balance is a debit balance. Determine whether there is a credit or debit balance for debits of $35.88, $1,405.90, $332.19, and $38.55 and credits of $1,089.34, $42.76, and $