1. What finance really is
Finance is just the set of decisions you make about money: how you earn it, how you spend it, how much you keep, whether you borrow, and what your money does while it waits. Companies and governments make the same decisions, only with more zeros.
Three questions cover almost all of it:
- Where does my money come from? A job, an allowance, a side hustle, gifts.
- Where does it go? Needs, wants, and the money you set aside.
- What is it doing while it waits? Sitting in a drawer, sitting in a bank account — or working for you.
That last question is the one this lesson is really about. Money that sits does nothing. Money that is invested grows — slowly at first, then surprisingly fast.
2. Saving vs. investing
People use the two words as if they meant the same thing. They don't.
| Saving | Investing | |
|---|---|---|
| What it's for | Money you'll need soon (a phone, a trip, an emergency) | Money you won't touch for years |
| Where it lives | A savings account | Stocks, ETFs, bonds — through an investment account |
| Risk | Almost none (your bank deposits are insured up to $100,000 by CDIC) | Goes up and down along the way |
| Reward | Low — around 1 to 4 % a year | Higher over time — the stock market has averaged about 7 to 10 % a year over long periods |
Example. You put $500 aside at 15. In a savings account paying 2 %, it's worth about $610 at 25. Invested in a broad stock index fund averaging 7 %, it's worth about $984 — and that is before you add a single extra dollar.
The rule of thumb: save what you need in the next 2 to 3 years; invest what you can leave alone for longer.
3. Budgeting: pay yourself first
A budget is not a punishment. It's a plan that decides where your money goes before it disappears. The simplest plan is the 50 / 30 / 20 rule:
- 50 % for needs — the things you must pay: transport, phone, lunches.
- 30 % for wants — the fun stuff. Yes, it's allowed.
- 20 % for your future — saving and investing.
Example. A part-time job pays you $400 a month. That's $200 for needs, $120 for wants, and $80 for your future. The trick that makes it work: move the $80 the day you get paid — "pay yourself first" — instead of hoping some is left at the end of the month. (Spoiler: it never is.)
4. Interest and compound interest
Interest is the price of money. When you borrow, you pay it. When you lend — and putting money in a bank account is lending it to the bank — you earn it. It's expressed as a percentage per year.
Simple interest is paid only on your original amount. Compound interest is paid on your original amount and on the interest you already earned. That tiny difference becomes a snowball:
| $1,000 invested at 7 % a year | After 10 years | After 20 years | After 40 years |
|---|---|---|---|
| Simple interest | $1,700 | $2,400 | $3,800 |
| Compound interest | $1,967 | $3,870 | $14,974 |
Notice the last column. Over 40 years, the money didn't grow 4 times — it grew almost 15 times, and most of that growth happened in the last 15 years. That is why starting early matters more than starting big: a 15-year-old who invests $1,000 and stops has more at 55 than a 30-year-old who invests $2,000.
The rule of 72. Divide 72 by the yearly return and you get roughly how many years it takes for money to double. At 7 %, 72 ÷ 7 ≈ 10 years. At 2 %, it takes 36 years.
5. Inflation: why cash quietly shrinks
Inflation is the general rise in prices over time. The Bank of Canada aims for about 2 % a year; in 2022 it jumped to 6.8 %, which is why everything suddenly felt expensive.
At 2 % a year, $100 kept in a drawer still says "$100" in ten years — but it only buys about $82 worth of what it buys today. Cash doesn't stay still: it slowly melts.
This is the reason to invest at all. Your money has to grow faster than prices just to stand still. A savings account at 1 % loses to inflation at 2 %. A diversified investment averaging 7 % beats it comfortably.
6. Risk and return: the trade-off that runs everything
In finance there is no free lunch. Anything that promises a higher return comes with more risk — a bigger chance that the value drops along the way. Think of it as a ladder:
- Savings account — almost no risk, almost no return.
- GICs and government bonds — you lend money for a fixed time and get a fixed rate.
- Index funds / ETFs — hundreds of companies in one basket; bumpy in the short term, steady over decades.
- Single stocks — one company; can double, can go to zero.
- Crypto and speculative bets — anything can happen, including losing everything.
Two things lower risk without lowering return: time (the longer you hold a diversified investment, the less the bumps matter) and diversification (not putting everything in one place — lesson 2). And one thing raises risk more than anything else: never starting.
In one sentence: earn, keep 20 %, invest what you won't need for years, let compound interest do the heavy lifting — and understand the risk you're taking before you take it.
Mini-quiz — did it stick?
Five questions, instant answers. Nobody is watching.