Understanding Signed Decimals

The video tutorial explains how to add signed decimals, focusing on two scenarios: adding numbers with different signs and adding numbers with the same sign. For different signs, the process involves subtracting the smaller absolute value from the larger and using the sign of the number with the larger absolute value. For the same signs, the absolute values are added, and the original sign is retained. Examples are provided to illustrate these rules, emphasizing the importance of aligning decimal points and borrowing when necessary.

What happens when you add a positive and a negative number?

• The result is always positive.

• The result is always negative.

• The result is always zero.

• The result depends on the larger absolute value.

When adding numbers with different signs, what is the first step according to the formal rules?

• Add the numbers directly.

• Subtract the smaller absolute value from the larger one.

• Multiply the numbers.

• Divide the numbers.

In the example of 8 and 2.9, what is the result of the subtraction?

• 6.1

• 5.1

• 4.1

• 7.1

Why is the sum of 8 and 2.9 negative?

• Because the negative number has a larger absolute value.

• Because 2.9 is larger.

• Because 8 is negative.

• Because the positive number is smaller.

What is the rule for adding numbers with the same sign?

• Divide their absolute values.

• Multiply their absolute values.

• Subtract their absolute values.

• Add their absolute values and use the original sign.

What is the absolute value of -4.58?

• 4.58

• 0

• 5.58

• -4.58

In the example of -4.58 and -2.976, what is the sum of their absolute values?

• 7.556

• 5.556

• 8.556

• 6.556

What is the final result of adding -4.58 and -2.976?

• -7.556

• 7.556

• -6.556

• 6.556

Why is the sum of two negative numbers also negative?

• Because they cancel each other out.

• Because their absolute values are subtracted.

• Because adding two losses results in a larger loss.

• Because the positive sign is used.

What should you remember when adding signed decimals?

• Subtract the numbers regardless of their signs.

• Ignore the signs and add directly.

• Follow the rules for different and same signs carefully.

• Always use the positive sign.