Adding and Subtracting Integers

This lesson covers the representation of subtraction using a number line. It explains how to add and subtract positive and negative numbers, both with the same and different signs. The lesson introduces algorithms for handling large numbers and demonstrates the equivalence of subtracting a negative number to adding a positive one. Key concepts include using zero sum pairs and understanding absolute values to determine the sign of the result.

What is one of the main goals of today's lesson?

• To learn multiplication of large numbers

• To understand how to use a number line for subtraction

• To memorize the multiplication table

• To practice division of fractions

When adding two positive numbers on a number line, in which direction do you move?

• To the right

• Upwards

• To the left

• Downwards

If you add -3 and -4, what is the result?

• -7

• 7

• -1

• 1

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

• The result is undefined

• The result is negative

• The result is zero

• The result is positive

In the example of 10 minus 4, why is the result positive?

• Because 4 is greater than 10

• Because there are more positives than negatives

• Because 10 is less than 4

• Because subtraction always results in a positive number

What is the first step in the algorithm for adding numbers with different signs?

• Add the numbers directly

• Find the absolute values of both numbers

• Divide the numbers

• Multiply the numbers

If you have -155 and +83, what is the result using the algorithm?

• -72

• 72

• -238

• 238

What is equivalent to subtracting a negative number?

• Multiplying by zero

• Adding a negative number

• Subtracting a positive number

• Adding a positive number

When subtracting -5 from 3, what is the result?

• -8

• 2

• -2

• 8

What is a useful tool for checking calculations involving positive and negative numbers?

• A dictionary

• A multiplication table

• Zero sum pairs and number lines

• A calculator