1. Add and Subtract Real Numbers Honors Math – Grade 8

2. What operation? Get ready for the Lesson An oil well has been dug to a depth of 1.7 miles. Additional drilling makes the well 1.2 miles deeper. What signed number expresses the final depth of the well? AdditionWhat are the addends?The well has been dug into the earth. A number line can be used to add signed numbers. Start at 0 and move to the left for negative #’s and to the right for positive #’s. KEY CONCEPT Adding Signed Numbers To add signed numbers with like signs: 1.Add their absolute values. 2.Use the sign of the addends for the sum.

3. KEY CONCEPT Adding Signed Numbers To add signed numbers with unlike signs: 1.Subtract the lesser absolute value from the greater absolute value 2.Use the sign of the addend with the greater absolute value. Simplify the absolute values. Subtract the Mixed Numbers. What is the LCD? Make equivalents. Borrow and subtract. 240 Use the sign of the rational number with the greater absolute value.

4. Subtract the lesser absolute value from the greater absolute value. Unlike Signs! Simplify the absolute values. Subtract the Decimals. Use the sign of the rational number with the greater absolute value.

5. Add the absolute values! Like Signs! Simplify the absolute values. Add the mixed numbers. What is the LCD? Use the sign of the addends for the sum. Add the Mixed Numbers.

6. Subtract the lesser absolute value from the greater absolute value. Unlike Signs! Fraction & Decimal Simplify the absolute values. Subtract the Decimals. Use the sign of the rational number with the greater absolute value. Change the fraction to a decimal!

7. KEY CONCEPT Subtracting Signed Numbers To subtract signed numbers: 1.Add its opposite. 2.Follow rules for adding signed numbers. Align the Decimal PointsAdd the opposite of the subtrahend. Apply the rule for adding unlike signs.

8. Add the opposite of the subtrahend. Apply the rule for adding like signs. Add the mixed numbers. What is the LCD? Add the Mixed Numbers. Rename the sum. Both addends are positive. The sum is positive!

9. Align the Decimal PointsAdd the opposite of the subtrahend. Apply the rule for adding unlike signs. Subtract the greater absolute value from the lesser absolute value. Simplify the absolute values.Subtract the decimals. Use the sign of the rational number with the greater absolute value.