Time Choices & Opportunity Cost
Everyone gets the same 24 hours every day. You cannot save time in a jar — you can only choose how to use it.
When you choose one thing, the next best thing you gave up is called the opportunity cost. If you spend your $3 on stickers, the opportunity cost might be the $3 you could have saved toward a ball.
Big rocks first: put important things like homework and chores into your day first, then fill the rest with play. If you play first, the important things often get squeezed out.
A to-do list helps. Write three things, do the most important one first, and check it off. Checking things off feels great!
You, what is one 'big rock' you could put first in your day tomorrow?
Learning objective
Name the opportunity cost of everyday choices with time and money.
Understand the mechanism
A choice always gives something up. Naming what you gave up helps you choose on purpose.
Time and money are both limited, so the same thinking works for both.
Put it to work
Before a choice, ask: what else could I do with this time or money? Pick the one you will be happiest about tomorrow.
Worked example
- 1
You have 30 minutes before dinner.
- 2
Option A: tablet. Option B: finish your reading log, which is due tomorrow.
- 3
Reading first means the opportunity cost is 30 minutes of tablet — but tomorrow is stress-free.
Ask 'what am I giving up?' before you choose.
Your practice lab
You have $5. A movie snack costs $5, or you could add $5 to your $15 bike savings. Name the opportunity cost of each choice.
Personal scratchpad · not graded or saved
Sam's Big Rocks
Sam always played first and did homework at bedtime, when he was tired and grumpy.
His mom showed him a jar: if you pour sand in first, the big rocks won't fit. If you put the big rocks in first, the sand fills in around them. Sam started doing homework right after snack time, and he still had time to play.
When important things go first, there is still room for fun.
Illustrative example — names and figures are composites for teaching.
List your three big rocks for a school day.
Example: Homework, feeding the cat, practicing piano.
Go deeper — outside resources
- CFPB — Money as You Grow · Consumer Financial Protection Bureau
- Khan Academy — Financial literacy · Khan Academy
Key ideas
- Time and money can only be used once
- Opportunity cost = the next best thing you gave up
- Big rocks first
Try it: Make a to-do list with three things for tomorrow. Star the most important one.
Quick check
1. What is opportunity cost?
2. Can you save time in a jar?
3. What does 'big rocks first' mean?
4. You spend $3 on stickers instead of saving for a ball. What is the opportunity cost?
5. How does a to-do list help?