Subtraction Using a Number Line

This video tutorial teaches how to subtract using a number line. It begins with an introduction to number lines, explaining their use in showing the order of numbers and performing addition. The tutorial then focuses on subtraction, detailing how to move left on the number line to find the difference. Common misunderstandings, such as moving in the wrong direction or counting points instead of units, are addressed. The video also demonstrates using groups of ten to simplify subtraction problems. Practical examples, like subtracting students, are provided to reinforce learning.

What does a number line show?

• The color of numbers

• The size of numbers

• The shape of numbers

• The order of numbers

When subtracting on a number line, which direction should you move?

• Upwards

• To the left

• Downwards

• To the right

What is the first step in using a number line to subtract?

• Start the number line at the sum

• Start the number line at zero

• End the number line with a smaller number

• End the number line with a larger number

How do you arrive at the difference when using a number line?

• By taking away units

• By moving to the right

• By adding units

• By multiplying units

What is a common mistake when using a number line for subtraction?

• Using a ruler

• Starting at zero

• Counting points instead of units

• Always moving to the left

Why is it incorrect to always move to the right on a number line?

• Because it is not allowed

• Because it is too slow

• Because subtraction requires moving left

• Because it increases the number

What should you do instead of counting points when subtracting?

• Count forwards

• Use a calculator

• Count backwards

• Jump or subtract full units

How can groups of ten help in subtraction on a number line?

• By adding more numbers

• By changing the direction of subtraction

• By simplifying the subtraction process

• By making the number line longer

In the example of 75 minus 23, how is 23 broken down?

• Into a group of fifteen and a group of eight

• Into two groups of ten and a group of three

• Into three groups of ten

• Into a group of twenty and a group of three

In the practical example, how many students are at school if 12 are sick?

• 12

• 78

• 56

• 66