The two ways that we can use a number line are given below. While both methods ultimately lead to the same answer, I believe that Method 1 offers a clearer, more efficient, and more visually appealing approach to solving this particular problem.
Here are two ways that you can use a number line to find 70-56:
Method 1:
1. Start at 70 on the number line.
2. Move 56 to the left.
3. We will end at 14.
Therefore, 70 - 56 = 14.
Method 2:
1. Start at 0 on the number line.
2. Move 70 to the right.
3. Move 56 to the left.
4. We will end at 14.
Therefore, 70 - 56 = 14.
Both methods show that 70 - 56 = 14.
I prefer Method 1 for the following reasons:
More intuitive and easier to follow: Method 1 directly represents the subtraction operation. We start at 70 and subtract 56 by moving that amount to the left. This aligns with how we conceptualize subtraction in everyday life: taking away something from an initial quantity.
Fewer steps: Method 1 requires only two steps, while Method 2 requires four. This makes it more concise and easier to remember.
More visually appealing: Method 1 involves a single, continuous movement on the number line, which is easier to visualize and understand compared to the two separate movements in Method 2.
Consistency with teaching methods: In most elementary schools, subtraction is initially taught by starting with a quantity and taking away a part, which aligns directly with Method 1. This makes it more familiar and relatable for students who are learning about subtraction.
While both methods ultimately lead to the same answer, I believe that Method 1 offers a clearer, more efficient, and more visually appealing approach to solving this particular problem.