# ChatGPT can be bad at basic math

ChatGPT can be bad at basic math sometimes. For example, mixed fractions.

On 12/4/23 I asked ChatGPT 4 about mixed fractions.

**Question 1: How do you calculate mixed numbers 1 8/12 x 3 2/10?**

It answers to convert the mixed numbers to fractions…

It says the result is 16/3

**Question 2: Can you multiply the whole numbers first and then the fractions?**

It answers “Yes, you can multiply the whole numbers first and then the fractions when dealing with mixed numbers…”

It says the result is 47/15

**Question 3: But you said the answer was 16/3 which is 5.33 and 47/15 is 3.13, which is the correct answer?**

This literally was the answer:

```
You are correct to point out the discrepancy. Let's review the calculations:
The initial calculation for 1 8/12 x 3 2/10 yielded 5 1/3 or 16/3 as the answer.
The second method, where I suggested multiplying the whole numbers first and then the fractions, should yield the same result if done correctly. Let's recheck this calculation:
The whole numbers 1 and 1 multiply to 3.
The fractions 8/12 and 2/10 need to be simplified before multiplication.
Let's recompute the multiplication of the fractions and then add it to the product of the whole numbers to ensure accuracy.
The rechecked calculation confirms that the product of 1 8/12 x 3 2/10 using the method of multiplying whole numbers first and then fractions is 47/15, which is approximately 3.13.
This suggests an error in the initial calculation. Let's revisit and correct the first method to ensure accuracy.
Upon rechecking the initial calculation, the product of 1 8/12 x 3 2/10 remains 5 1/3 or 16/3, which is approximately 5.33.
Therefore, the discrepancy arises from a mistake in the second method of calculation. The correct approach should yield the same result as the first method. Let's identify and correct the error:
The product of the whole numbers (1 and 3) is indeed 3.
The fractional parts 8/12 and 2/10 need to be multiplied and then added to the whole number product. This step seems to be where the error occurred.
Let's correct this step and calculate again.
Upon re-evaluating, the correct product of 1 8/12 x 3 2/10 using the second method (multiplying the whole numbers first and then the fractions) is indeed 47/15, which is approximately 3.13.
This result differs from the initial calculation. It seems there was a fundamental error in the initial method. The correct answer should be 47/15 or approximately 3.13, as obtained through the second method. My apologies for the confusion earlier.
```

Somehow it thinks that the second answer `47/15`

or `3.13`

is the correct answer.

**Correct answer**

Mixed fractions

```
1 8/12 x 3 2/10
```

Reduce the fraction `1 8/12`

equals `20/12`

Reduce the fraction `3 2/10`

equals `32/10`

Now multiply

```
20/12 x 32/10 = 16/3
```

The answer is `5.333`

. ChatGPT4 thinks the answer is `3.13`