Writing prompt w14: compound interest for a 12-year-old, answered by fifteen AI models
Prompt w14 (beginner explanation) was answered 3 times by each of 15 models. This page lists every output, the rater's rubric scores and whether each output passed the format rule (exactly 3 sentences). Best mean rubric score on this prompt: Qwen2.5 7B.
Tested by us on 2026-10-26 (America/Chicago): open-weight models run locally on a CPU-only machine, outputs rated by a separate model (Mistral 7B Instruct v0.3) that is not a writer in this test. Indicative results, not a benchmark, and not a statement about any vendor's hosted models.
Summary
Explain how compound interest works to a 12-year-old in exactly three short sentences.Format rule checked by code: exactly 3 sentences.
| Model | Mean rubric score (1 to 5) | Format rule passed |
|---|---|---|
| Llama 3.2 1B | 4.53 | 3 of 3 |
| Phi-3.5 mini | 4.60 | 3 of 3 |
| Llama 3.2 3B | 4.60 | 3 of 3 |
| Gemma 2 2B | 4.60 | 3 of 3 |
| Gemma 3 1B | 4.67 | 3 of 3 |
| SmolLM2 1.7B | 4.67 | 3 of 3 |
| Qwen2.5 7B | 4.80 | 2 of 3 |
| Qwen2.5 3B | 4.60 | 2 of 3 |
| Qwen2.5 1.5B | 4.60 | 0 of 3 |
| Qwen3 0.6B (non-thinking) | 4.53 | 0 of 3 |
| Qwen2.5 0.5B | 4.60 | 0 of 3 |
| Falcon3 3B | 4.80 | 3 of 3 |
| Granite 3.3 2B | 4.73 | 0 of 3 |
| Qwen3 1.7B (non-thinking) | 4.73 | 2 of 3 |
| TinyLlama 1.1B Chat | 4.13 | 0 of 3 |
Llama 3.2 1B: all 3 outputs
Here's an explanation of compound interest that a 12-year-old can understand:
When you save money, like in a bank account, it earns interest on itself, kind of like a magic machine that makes your money grow faster. This interest is added to your initial savings, so that next time you save, it gets even more money to add to your account. By the time you're 12 years old, that initial money you put in will have grown a lot and might be worth a lot of money!Here's an explanation of compound interest that a 12-year-old can understand:
When you put your money in a savings account or investment, it earns interest, which means it gets a little bit more money at the end of the year. This extra money is added to the original amount, so it can grow faster over time. The next year, the interest you earned gets added to the principal (the original amount), making your money grow even more quickly!Compound interest is like a magic machine that helps your money grow over time. When you save money with a high interest rate, you earn more money that gets added to your account, making it grow faster. This magic machine keeps working for you, so your money can grow really, really fast over time.Phi-3.5 mini: all 3 outputs
Compound interest is like a snowball rolling downhill; it starts small but grows bigger as it picks up more snow (or money) over time. Each year, you earn interest not just on your original amount, but also on the interest that has already been added to your savings. This means that the longer you leave your money in the bank, the more it grows, because you're making money on top of money!Compound interest is like planting a tree and watching it grow; you start with a small seed (your initial amount of money), and over time, it grows larger because the tree (your money) makes more seeds (interest) that also grow. These new seeds then produce their own seeds, and this cycle repeats, making your tree and all its seeds grow faster and bigger than if you had just watched one tree grow on its own. This is why saving money in a bank account, where your money earns interest, can make you have more money over time than if you just kept it in a piggy bank.Compound interest is like planting a tree and watching it grow; you start with a small amount of money, and over time, it earns more money not just from your initial amount, but also from the extra money it has made. This means you earn interest on your interest, so the more time you let it grow, the more money you end up with. It's like magic money-making, but it's really just math!Llama 3.2 3B: all 3 outputs
Here's an explanation of compound interest that a 12-year-old can understand:
Imagine you put money in a savings account that earns 5% interest per year. At the end of the first year, you'll have 5% of your original money back, so you'll have a total of 105% of your original money. But here's the cool thing: in the second year, you'll earn interest on the new total amount of money, not just the original amount, so you'll actually earn 5.25% interest in the second year!Here's an explanation of compound interest that a 12-year-old can understand:
Imagine you put money in a savings account that earns a certain interest rate, like 5% per year. Over time, not only do you earn 5% interest on the original amount, but you also earn interest on the interest that's already been added, so it grows faster. For example, if you started with $100 and it earns 5% interest, after one year you'll have $105, and after two years you'll have $110.25!Here's an explanation of compound interest that a 12-year-old can understand:
When you save money in a special account, like a savings account or a certificate of deposit (CD), it earns interest, which is like a thank-you from the bank for letting them keep your money. If the interest is added to your original amount, it starts earning interest too, and this creates a snowball effect that makes your money grow faster and faster over time. For example, if you start with $100 and it earns 5% interest per year, after one year you'll have $105, and in the second year, it will earn interest on that new amount, so you'll have even more money!Gemma 2 2B: all 3 outputs
Imagine a snowball that gets bigger and bigger as it rolls down a hill. Compound interest is like that snowball, where you earn interest not only on your original money but also on the interest you've already earned. The more time you let your money grow with compound interest, the more powerful it becomes, just like a snowball getting bigger and bigger.Imagine you have money in a special bank account where it grows a little bit each year. That growth is called "compound interest," and it means you earn interest on both your original money and any interest you already earned. The more time your money stays in the account, the more it grows because interest is calculated on the growing amount, creating a snowball effect!Imagine you have a special piggy bank that earns a little bit more money every year. That extra money is called compound interest, and it's like magic because it grows on top of your original savings! The longer you save, the more compound interest you earn, making your money grow like a snowball rolling down a hill.Gemma 3 1B: all 3 outputs
Okay, here’s a three-sentence explanation of compound interest for a 12-year-old:
Imagine you’re lending money to someone, and they start earning interest on it. Then, they start lending it back to you, and you earn interest on *that* too! Over time, this "interest on interest" grows your money really quickly – that’s compound interest!Okay, here’s a three-sentence explanation of compound interest for a 12-year-old:
Imagine you invest money and it earns interest, like a little bonus! Then, when you start earning interest, you get even more interest – that’s called compounding. So, your money grows faster over time because it’s earning interest on itself!Imagine you lend your parents money, and they give you a little bit back each year. That's compound interest – it’s basically earning interest on your original investment, and then earning even more interest on that new amount! Over time, your money grows faster and faster because of this repeated interest.SmolLM2 1.7B: all 3 outputs
Compound interest is like when you save money in a bank account and the bank adds extra money to your savings over time. This extra money is called interest, and it grows the more you save. So, if you save $100 in a year with a 5% interest rate, in the next year, you'll have $105 ($100 + $5), and in the third year, you'll have $110.50 ($105 + 5%) and so on.Compound interest is like a magic trick where you start with a small amount of money and let it grow over time, but instead of just adding more money, the amount you have also earns interest on its own. For example, if you put $100 in a savings account with a 5% interest rate, after one year you'll have $105, and after the next year, you'll have $110.25, because the $5 you earned in the first year also grew by 5%, making it $5.25. This is called compound interest, and it's a great way to make your money grow fast.Compound interest is when you earn money from both the money you originally put in and any interest you've already earned. It means that the interest you get at the end of each period is added to the principal, so you can earn more interest in the next period. For example, if you put $100 in a savings account with 5% compound interest per year, you'll earn $5 at the end of the first year, then $5.25 at the end of the second year (because the $5 earns $0.25 interest), and so on.Qwen2.5 7B: all 3 outputs
Compound interest means your money grows because you earn interest on the interest you've already earned, not just on the original amount. It's like getting more birthday presents by putting your last present in a bigger box and getting presents for that one too! This makes your savings grow faster over time.Compound interest is like a snowball that rolls down a hill and gets bigger as it rolls. You earn interest on your money, and then you earn interest on the interest you already got, making your savings grow faster over time.Compound interest is like a snowball that rolls down a hill and gets bigger as it rolls. It means your money earns interest not just on the original amount but also on any interest it has already earned. This makes your money grow faster over time!Qwen2.5 3B: all 3 outputs
Compound interest is like magic money. It grows bigger over time because it earns interest on the money you put in plus any interest it already made. It's super helpful for saving money or growing investments.Compound interest is like magic money. It grows by adding the extra money you earn to your original amount, so you get more interest on more money over time.Compound interest is like magic money. It grows faster over time because you earn interest on both the original money and any interest you already got. It's like planting a seed; you get more seeds to plant next year!Qwen2.5 1.5B: all 3 outputs
Compound interest is like getting interest on your interest. When you save money, it grows faster because you earn interest on the money you've already saved. It's like having your allowance doubled each week, then your doubled allowance doubled again, and so on. This is how your money grows bigger over time.Compound interest is like earning interest on interest. Imagine you have $100 and it earns 10% interest each year. After one year, you have $110. But in the next year, you earn 10% on $110, which is $11, so you have $121. Each year, the interest you earn is based on the total amount you had at the start of the year. This means your money grows faster and faster over time.Compound interest is like a snowball rolling downhill - it gets bigger and bigger over time. When you save money, it earns more money because the interest you earn earns more interest too.Qwen3 0.6B (non-thinking): all 3 outputs
Compound interest is like earning interest on your interest! Every year, your money grows by a percentage of the interest you earn. For example, if you save $100 at 10% interest, you'll earn $10 each year, and the interest on that $10 will also grow, increasing your total. So it's like your money "bounces" on itself.Compound interest is like earning interest on your savings, not just on the principal amount. Every year, your interest adds to your total, so it grows faster over time. For example, if you save $100 and earn 10% interest, your total after one year is $110. Then, the interest for the next year is added to $110, so it becomes $121. It grows faster each year because the interest is being reinvested.Compound interest works like a savings account where your money earns interest not just on the initial principal, but also on the interest you have already earned. So, each time your money grows, it gets richer, and you earn more money from it.Qwen2.5 0.5B: all 3 outputs
Compound interest is like a special kind of money that grows faster because it's added to the original amount, making it even more valuable! Imagine you have a piggy bank that's already holding some coins. When you add more coins to it, those coins are still there, but they're earning you more coins as time goes on. This keeps the amount of coins in your piggy bank growing, even though they may not be as noticeable as they would be with regular savings!Compound interest is like saving in a piggy bank, but for grown-ups. When you save your money, the interest you earn each year helps make your money grow faster. So, after one year, if you had $100, you'd have $101. If you had $100 after two years, you'd have $110. This means your money keeps growing and you end up with much more than you started with!Compound interest is like adding a little extra interest to your savings, which grows even more because it builds on the previous interest you already earned. It's like having a magical wand that doubles your money every year, making it even more valuable.Falcon3 3B: all 3 outputs
Compound interest means that you earn interest not just on your original money, but also on the interest you've already earned. This makes your money grow faster over time. So, the more often interest is added, the more your money grows.Compound interest means that you earn interest not just on your original amount, but also on the interest you've already earned. This makes your money grow faster over time, like a snowball rolling downhill. It's like getting extra money for the money you already have!Compound interest means that when you earn money on your savings, you also earn interest on the interest you've already earned. This makes your money grow faster over time. So, the more often interest is added, the more you'll have in the long run.Granite 3.3 2B: all 3 outputs
Compound interest is like earning interest not just on your original money, but also on the interest that grows over time. Imagine you have $100 and your bank gives you 5% interest each year. In the first year, you get $5. But in the second year, you not only have $105 but also $5 more from the first year's interest, making it $110. The next year, you earn $5 on $110, and this process continues, growing your money faster each year due to the interest on previously earned interest.Compound interest is like when your piggy bank earns interest not just on your money, but also on the interest it already earned. Imagine your piggy bank gives you 5% interest each year. If you start with $10, you'll get $1 in interest the first year, but the next year, you'll earn interest on $11, not just $10. This means you make a little extra money on top of the original amount, and it grows over time.Compound interest is like getting interest on interest. Imagine you have $100, and your bank gives you 5% interest each year. In the first year, you earn $5, so you have $105. The next year, you earn 5% on $105, which is $5.25, adding to your total. Over time, this "interest on interest" grows your money faster than simple interest.Qwen3 1.7B (non-thinking): all 3 outputs
Compound interest is like when your money grows by earning money on top of the money you already have. Every time your money grows, it earns more interest. Over time, this interest starts to grow faster because it's calculated on the new amount. After a while, your money becomes really big because of compound interest!Compound interest is like letting your money grow by earning interest on the interest you already earned. Every time your money grows, the new interest is added to your total, so your money grows faster over time. The more money you have, the more interest you earn, and that's why it grows so fast!Compound interest is when your money grows faster because you earn interest on your original money and on the interest you've already earned. It's like your money is "working" for you more and more each year. Over time, even small amounts can grow a lot because of compound interest.TinyLlama 1.1B Chat: all 3 outputs
Compound interest is a mathematical concept that refers to the growth of an amount over time, due to the fact that interest is paid repeatedly on the principal amount. It is based on the simple fact that the interest earned is multiplied by a fraction, which means the amount grows exponentially.
For example, if you deposit $1000 into your bank account at the end of a year and you earn 10% interest per year, your final balance after one year will be $1133.50. If you deposit another $1000 in the same account, the interest earned during the same year will be $1182.00, or an increase of $488.50.
Compound interest is calculated based on the original principal amount, the interest rate, and the number of years over which the interest is earned. Since the interest rate is a constant factor, compound interest is an exponential growth rate.
So, if you deposit $1000 and earn 10% interest per year, your final balance after 10 years will be $2000.50. Since interest is calculated as a fraction, the compounded interest is calculated by taking the initial principal amount multiplied by the interest rate, multiplied by the number of years over which interest is earned, and then divided by the original principal amount.
This is an interesting concept for children to understand because it demonstrates exponential growth, which is a familiar concept to many young people. It also illustrates the importance of saving money and investing for the future.Compound interest is a mathematical concept that refers to the interest paid on an amount invested or borrowed over a certain period. When you invest money, you can earn interest on that money. The longer you invest, the more interest you earn.
For example, let's say you invest $1000 in a savings account over a period of 5 years. The interest earned during this time is calculated as (5 x 1000) / 365 = 1,000 x 2.5 = $2,500.
After the 5th year, the interest earned on your savings account is calculated as (5 x 1000) / 365 = 1,500 x 2.5 = $3,250.
So, over the 5 years, you earned a total interest of $2,500.
In summary, compound interest is the interest earned on the interest earned on the initial investment. It is calculated by taking the interest rate multiplied by the number of years in the loan or investment.Compound interest is a mathematical concept that allows an interest rate to grow over time. Here's how it works in a simple example:
Let's say you invest $100 for 12 years. During that time, you earn an interest rate of 5% per year. After 12 years, you'll have earned an interest rate of $105.25.
Here's how compound interest works: The interest you earned during the first 12 years, $5, is added to the $100 you invested at the beginning of the 12th year, creating a new balance of $105.
The interest you earned during the second 12 years, $15, is added to the $105.25, creating a new balance of $120.25. And so on, creating an ever-increasing balance.
So, by the end of the 12th year, your balance will be $120.25. The interest you earned during those 12 years, $105.25, added to the $120.25, created $125.45 in compound interest. This means that every year, your balance will grow by $10.45, or 10.45% per year.Related
Markdown version for agents: /tests/writing-prompt-w14.md