Could someone please explain this to me: Use counters to model the sum: 8 + ( -3 ). How I solved this was : 8 - 3 =5.
Use 8 counters (objects) and take 3 away.
So I could say: Start with 8 marble counters and take away 3 marble counters. There should be 5 marble counters left. Is this how I should explain this question: Use counters to model the sum: 8+(-3.
Yes. That looks good.
Sure! I can explain how to use counters to model the sum 8 + (-3).
When we talk about using counters to model addition, we usually represent positive numbers with regular counters, and negative numbers with counters represented by the opposite color or direction.
To model the sum 8 + (-3), you would start by representing the positive number 8 using eight regular counters. You can imagine these counters as small objects, such as coins or tokens.
Next, to represent the negative number -3, you would use three counters of the opposite color or direction. For example, if you used red counters for positive numbers, you could use three blue counters for the negative number -3.
Now, to combine these counters and find the sum, you need to understand that adding a positive number is like moving forward, whereas adding a negative number is like moving backward.
Starting with your eight counters representing the positive number 8, you can imagine moving forward on a number line by placing each counter one after the other.
Then, when you need to add the negative number -3, you can imagine moving backward on the number line by removing three of the counters you previously placed.
By doing so, you would find that you have five counters remaining. Therefore, the sum of 8 + (-3) using this model would be 5.
In the way you solved it, by subtracting 3 from 8, you reached the correct answer of 5. This is because subtracting a negative number is the same as adding the positive of that number. So, 8 - (-3) is equivalent to 8 + 3, which equals 11. However, note that this approach is slightly different from using counters to model addition.