Gemini 3.8 Flash · Math

Gemini 3.8 Flash for math: our test runs

Gemini 3.8 Flash ran our 5 math prompts in llmwise, through the same pipeline your messages take. Here's every reply as it came, whether it passed, what it cost and what it counts as on Pro, next to the other models.

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Based on 5 of our test runs on September 27, 2026, through OpenRouter with the app's own prompt and settings.

Short answer

In our test runs on September 27, 2026, Gemini 3.8 Flash passed 5 of 5 of our math prompts (both hard ones): tied 1st of 15 models. Each reply counted as 1 message on Pro, where it has 250 a month, and cost $0.0014 to run on average.

Prompt by prompt

Each of the 5 math prompts, and how Gemini 3.8 Flash's reply did.

Gemini 3.8 Flash on each math prompt
Prompt	Result	Cost	Time
A discount, then sales taxEveryday	Passed: Final answer 66: right.	$0.0007	2.5 s
Pens at 3 for $4Everyday	Passed: Final answer 3 sets of 3 pens and 1 single pen for 13.50: right.	$0.0017	4.7 s
Compound interest over three yearsEveryday	Passed: Final answer 315.25: right.	$0.0009	2.1 s
Four-digit numbers whose digits sum to 9Hard	Passed: Final answer 165: right.	$0.0022	4.7 s
The highest of three dice is a 5Hard	Passed: Final answer 61/216: right.	$0.0018	4.9 s

Every math reply from Gemini 3.8 Flash

A discount, then sales tax
An everyday prompt: “A discount, then sales tax”, in full.
Passed: Final answer 66: right.
```
1. Calculate the discount: $80 \times 0.25 = $20.
2. Calculate the discounted price: $80 - $20 = $60.
3. Calculate the sales tax: $60 \times 0.10 = $6.
4. Calculate the total cost: $60 + $6 = $66.

Final answer: $66
```
430 tokens in, 89 out · 2.5 s · $0.0007 · 1 message on Pro · answered by google/gemini-3.8-flash via Google · September 27, 2026
Pens at 3 for $4
An everyday prompt: “Pens at 3 for $4”, in full.
Passed: Final answer 3 sets of 3 pens and 1 single pen for 13.50: right.
```
To get exactly 10 pens at the lowest cost, buy as many 3-pen deals as possible:

* 3 deals of 3 pens = 9 pens for $12.00 ($4.00 × 3)
* 1 single pen = 1 pen for $1.50

Total cost: $12.00 + $1.50 = $13.50

Final answer: 3 sets of 3 pens and 1 single pen for $13.50
```
431 tokens in, 354 out (240 of them reasoning) · 4.7 s · $0.0017 · 1 message on Pro · answered by google/gemini-3.8-flash via Google · September 27, 2026

Compound interest over three years

An everyday prompt: “Compound interest over three years”, in full.

Passed: Final answer 315.25: right.

To find the total amount $A$ after 3 years:
$A = P(1 + r)^t$
$A = 2000 \times (1 + 0.05)^3$
$A = 2000 \times (1.05)^3$
$A = 2000 \times 1.157625 = 2315.25$

To find the interest earned:
$\text{Interest} = A - P = 2315.25 - 2000 = 315.25$

Final answer: $315.25

429 tokens in, 148 out · 2.1 s · $0.0009 · 1 message on Pro · answered by google/gemini-3.8-flash via Google · September 27, 2026

Four-digit numbers whose digits sum to 9

A hard prompt: “Four-digit numbers whose digits sum to 9”, in full.

Passed: Final answer 165: right.

Let the four digits be represented by $a, b, c,$ and $d$, where $a \in \{1, 2, \dots, 9\}$ and $b, c, d \in \{0, 1, \dots, 9\}$.

We need to find the number of integer solutions to:
$$a + b + c + d = 9$$

Let $a' = a - 1$ so that $a' \ge 0$. Substituting gives:
$$a' + b + c + d = 8$$

Since the sum is $8$, no individual variable can exceed $8$, so the constraint that digits must be $\le 9$ is automatically satisfied.

Using the stars and bars formula, the number of non-negative integer solutions is:
$$\binom{8 + 4 - 1}{4 - 1} = \binom{11}{3} = \frac{11 \times 10 \times 9}{3 \times 2 \times 1} = 165$$

Final answer: 165

404 tokens in, 495 out (260 of them reasoning) · 4.7 s · $0.0022 · 1 message on Pro · answered by google/gemini-3.8-flash via Google · September 27, 2026

The highest of three dice is a 5

A hard prompt: “The highest of three dice is a 5”, in full.

Passed: Final answer 61/216: right.

To find the probability that the highest number showing on three fair six-sided dice is exactly 5:

1. The total number of possible outcomes when rolling three dice is $6^3 = 216$.
2. The number of outcomes where all three dice show a number less than or equal to 5 is $5^3 = 125$.
3. The number of outcomes where all three dice show a number less than or equal to 4 (meaning no 5 is rolled) is $4^3 = 64$.
4. The number of outcomes where the maximum number is exactly 5 is $125 - 64 = 61$.

Thus, the probability is $\frac{61}{216}$.

Final answer: 61/216

421 tokens in, 392 out (220 of them reasoning) · 4.9 s · $0.0018 · 1 message on Pro · answered by google/gemini-3.8-flash via Google · September 27, 2026

How it compares on math

Gemini 3.8 Flash beside the job's picks among every model. 14 models share the hard-problems pick, Gemini 3.8 Flash among them.

Gemini 3.8 Flash beside other models on math
Model	Passed	On Pro	Cost per reply
GLM 5.3Our pick: hard problems (shared), best value	5 of 5	250 a month on Pro	$0.0004
GLM 5.3 FlashOur pick: hard problems (shared), everyday	5 of 5	60 a day on Pro	$0.0002
Gemini 3.8 FlashOur pick: hard problems (shared)	5 of 5	250 a month on Pro	$0.0014

On Pro: Pro's count on each model. Cost: what OpenRouter charged us per reply, on average.

Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.

How these runs were done

Final answer. Automatic. The reply's last “Final answer:” line must hold the right value.

How the runs were done, and every math prompt.

Gemini 3.8 Flash, and math, elsewhere

Questions

Is Gemini 3.8 Flash good for math?

In our test runs it passed 5 of 5 math prompts, tied 1st of the 15 models in llmwise. Every reply is on this page, so you can judge them yourself.

How many of my messages does a math reply from Gemini 3.8 Flash use?

1 message each on Pro, where it has 250 a month on Pro. The price of a message is fixed and shown before you send it, however long the reply.

How were these runs done?

The same way for every model: each prompt sent through llmwise's own pipeline, each reply checked the same way. The methods page has every prompt and how each is scored.

Claude, GPT, Gemini, DeepSeek, Grok, Kimi, and GLM, in one chat.

See what a message costs before you send it. Free is 5 messages to try; sign in with an email link, no password or card.