Resources have limits

Paper packet. Every task here also exists on screen, where it is checked automatically; answers written on paper are not assessed by Nydus. When you are back at a device, enter your answers there.

1. What you will learn

2. Starting point

Add whole numbers and keep the resource's unit with the calculation. A plan is feasible when it fits every supplied limit.

3. Words for this lesson

4. A resource has possible uses

A resource is something used to do or make something. Time, materials, tools, space and people's effort can all be resources. A class may have a box of card, a pair of scissors and half an hour to make signs. The signs are what the class hopes to produce. The card, scissors, time and effort help make that possible. Naming the resource is the first step in finding a limit.

Scarcity means that available resources cannot meet every competing use people would like them to meet. Suppose a room is available for one hour. One group wants the whole hour for music and another wants the same room for a different activity during that hour. If the activities cannot happen together, both plans cannot be carried out as requested. The limit remains even if nobody pays to use the room. Scarcity concerns what can be done with the available resources, not only what money can buy.

Always name the place, time and uses being considered. A room may be available tomorrow but already occupied this afternoon. A tool may be plentiful in one building and unavailable in another. Saying 'there are not enough' becomes useful only when we explain enough of what, for which uses, and when. This makes the comparison something another person can check.

People can respond to scarcity by choosing, sharing where possible, changing a plan, waiting, or finding more resources. Each response needs its own facts. We cannot assume that waiting is possible when a task has a fixed deadline, or assume that two people can share equipment safely when the case says they cannot. A clear description of the limit comes before a decision about how to respond.

Term	What it means
Resource	Something used to do or make something.
Scarcity	Available resources cannot meet all competing uses people would like.
Feasible	Possible with the stated resources and rules.
Rivalry	One person's use reduces the use available to another.
Remainder	The unused amount after the stated uses are met.

Another way: Compare the total with the available amount

A group has ten pieces of card. One display uses six pieces and a second uses five. Doing both in the stated way would require eleven pieces. Six plus five equals eleven, which is one more than ten. This plan is not feasible: feasible means possible with the supplied resources and rules. The arithmetic does not tell the group which display matters more. It tells the group that it must change something if it wants a workable plan.

Another plan uses four pieces for the first display and five for the second. Together they use nine. Nine is less than ten, so that plan fits the card limit and leaves one piece. We have not shown that it meets every other requirement. It might also need glue, time or wall space. Passing one resource check is not the same as passing all of them.

When the total use equals the available amount exactly, the plan fits with no remainder. A plan that uses six pieces and four pieces uses all ten. There is no spare card, but that is different from being short of card. Keep three possibilities distinct: a plan can fit with something left, fit exactly, or require more than is available.

Check a feasible plan by adding its uses and its remainder. Four plus five plus one equals ten. Check an infeasible plan by adding the available amount and the extra amount needed. Ten plus one equals eleven. These checks put the comparison back together and help catch an answer that has reversed the shortage and the remainder.

Another way: Time is a resource even without a price

An afternoon can feel long, but it still has a limited number of minutes. Suppose a club has thirty minutes before the room closes. Putting supplies away takes ten minutes, and its planned game takes twenty-five. The activities require thirty-five minutes if they cannot overlap. That is five minutes more than the available thirty. More enthusiasm does not add those minutes to the schedule.

The group might shorten the game, begin earlier if permission is available, or carry out some tasks at the same time if the case allows it. It should not silently assume that everyone can do two activities at once. A schedule is a model of what happens when. Its answer depends on whether activities must happen one after another or can overlap.

An hour used for one purpose may prevent another use of that same hour. But not every shared experience uses up an extra hour for every additional person. Several people can hear the same announcement at the same time. We must describe how the resource works instead of applying one counting rule to everything. In the exercises, a statement such as 'the tasks must happen one after another' makes the time calculation clear.

Having more money does not remove every time limit. A person might pay for help with a task, but the helper also uses time and effort. There are still only so many minutes before a deadline. This is one reason scarcity is different from poverty. People with many possessions still face choices about limited time, attention, space and other resources.

Another way: Sharing and scarcity ask different questions

Some resources are used up or occupied when a person uses them. If there is one seat and one person sits in it, another cannot occupy that same seat in the same way at the same time. Economists call this rivalry. It tells us what one person's use does to another person's possible use. It is useful information, but it is not the complete meaning of scarcity.

A recorded story can be heard by another listener without removing the story from the first listener. The information is shareable in a way that a single seat is not. Yet recording that story may have required the author's time, a microphone, electricity and storage. Those resources have other possible uses. It would be wrong to conclude that making and providing recorded stories never involves scarce resources.

Compare the two questions carefully. 'Can another person use this same thing without reducing my use?' asks about sharing or rivalry. 'Can the available resources provide every use people want?' asks about scarcity. A good answer can say that the recording is shareable while the time and equipment used to create and provide it are limited. There is no contradiction between those statements.

In this course, count only the limits the case actually supplies. A story might be available on a device with no extra listening fee, while the device's battery lasts for only a certain time. The zero fee does not make the battery last forever. On the other hand, do not invent a battery shortage when the question gives unlimited access for the activity. Explain the boundary of the particular resource problem.

Another way: A shortage is not the whole idea of scarcity

A shop may run out of notebooks at its current price on a particular morning. That is a shortage in an everyday sense: people want more notebooks right then than are available. Later we will use a more precise market definition that compares quantities demanded and supplied at a stated price. For now, notice that the morning's shortage can end when more notebooks arrive or fewer people want them.

Scarcity is the broader need to make choices with limited resources. Even when a shop has enough notebooks for everyone currently buying one, producing notebooks still uses paper, equipment, energy and people's work. Those resources could have been used in other ways. Having full shelves does not prove that society can provide every desired thing without giving up any alternative use.

Rare and scarce are also different words. Something can be unusual without anyone wanting to use it. An unusual mark on a scrap of paper is rare, but its rarity alone does not establish a difficult resource choice. A common resource such as an hour of work can still be scarce relative to the many tasks people would like completed during that hour.

These distinctions prevent an overly quick label. Ask what is available, what uses are proposed, and whether those uses can all be met. The answer may be that the particular plan fits. That does not prove there will never be a resource limit. It means the specified plan passes the specified check, which is a precise and useful conclusion.

Another way: Change one part and check again

A useful way to understand a limit is to change one part of the case and repeat the comparison. If ten cards cannot meet uses of six and five, an extra card makes that same plan fit exactly. Alternatively, reducing one use by a card also makes it fit. These two changes reach the same card total through different actions. Their other consequences may differ.

Do not call a plan improved merely because it uses fewer materials. It must still meet its purpose. A bridge made from fewer pieces may no longer hold the model it is supposed to support. We compare feasible ways of achieving the stated task rather than treating every reduction as automatically better. The case must tell us whether a revised method still works.

We can now give a complete resource explanation: 'There are twelve minutes available. The two tasks take seven and eight minutes in sequence. They need fifteen minutes, so the plan exceeds the limit by three.' This statement identifies the resource, its quantity, the proposed uses, the rule about timing and the amount of the conflict. It leaves the choice of which task to change open until we know the purpose and priorities.

5. A library room with one afternoon slot

A library lends a small activity room to a neighborhood group from four o'clock to five o'clock. The group has sixty minutes in total. Its proposed program includes twenty minutes of storytelling, twenty-five minutes of craft work, and twenty minutes of cleaning. The library requires the cleaning to happen inside the booked hour. These activities use the same work area and must happen one after another.

Add the proposed uses: twenty plus twenty-five plus twenty equals sixty-five minutes. Compare that with the sixty available minutes. The proposed program exceeds the booking by five minutes. The room has no hire fee, but a zero fee does not remove this time conflict. The resource being checked is the room's available time, not the group's money.

The organizer considers shortening the craft work to twenty minutes while keeping the storytelling and cleaning times unchanged. The revised total is twenty plus twenty plus twenty, or sixty minutes. This version fits exactly. It is feasible under the time rule if the shorter craft activity still meets its purpose. The organizer must check that practical detail rather than assume that any shorter activity will work.

An extra donated box of crayons might be useful, but it would not itself add five minutes to the room booking. Nor can the group count next week's room time as time available this afternoon. The resource comparison makes the immediate constraint visible without deciding whose preferred activity deserves more time. That decision would require the group's goals and an agreed way of choosing.

6. A tempting mistake

A free price does not remove time or material limits. A shareable idea can still require scarce resources to create or provide.

7. A plan that exceeds the card supply

8. A time plan with a remainder

9. Changing one use while preserving the task

10. Nine minutes and seven minutes in a twenty-minute slot

11. Guided practice

There are 10 card pieces. Two simultaneous displays require 6 and 5 separate pieces. Write the total needed, extra amount needed beyond the supply, and unused amount if the plan fits. Use zero for the amount that does not apply.

12. Guided practice

Fill the time check for sequential tasks lasting eight and five minutes within a twenty-minute booking.

13. Guided practice

14. Practice

A box has 15 blocks. Two simultaneous models need 4 and 8 blocks. Write the total needed, extra amount needed beyond the supply, and unused amount if the plan fits. Use zero for the amount that does not apply.

15. Practice

A schedule has 24 minutes. Three tasks take 5, 11 and 8 minutes in sequence. Write the total needed, extra amount needed beyond the supply, and unused amount if the plan fits. Use zero for the amount that does not apply.

16. Somewhere new

A community garden has 16 planting trays. Its three simultaneous seed projects need 7, 6 and 5 separate trays. Write the total needed, extra amount needed beyond the supply, and unused amount if the plan fits. Use zero for the amount that does not apply.

17. Lesson test

Lesson test: one question per skill, one attempt each, no hints. Your answers are checked when you submit.

18. Test question

A display case has 20 places. Three exhibits require 6, 5 and 7 places, with no overlap. Write the total needed, extra amount needed beyond the supply, and unused amount if the plan fits. Use zero for the amount that does not apply.

19. What you can do now

Explain how to compare competing uses with a stated resource limit. Show a fresh example and check its result.

	Your result
Total needed
Extra needed
Unused

	Available time	Materials	Space
The hall closes in twenty minutes
Only eight wooden pieces are ready
The meeting table has four places
The helper can work for one hour

	Your result
Total needed
Extra needed
Unused

	Your result
Total needed
Extra needed
Unused