Three jars and the floors

Three jars, one ledger

Every kid in CubbyJar has three jars: Spend, Save and Give. It is tempting to picture them as separate little accounts tucked off to the side, but that is not how the ledger sees them. Each jar is a liability account on the same family ledger that holds the checking account, the credit card, and everything else the household tracks. A liability account is money the household owes somebody. Here, the household owes the kid whatever the three jars add up to.

That has one useful side effect worth spelling out plainly: no money is actually held by CubbyJar. The family’s cash sits wherever it already sits, a checking account, a wallet, wherever it lives day to day. The jars are the record of what the household has promised to hand over. When a payday adds money to a jar, the household’s promise to that kid gets bigger, and the household’s own budget notices the change on the same ledger.

Floors

CubbyJar has exactly one definition of a floor, and it is the sentence that appears on the screen where a grown-up sets one: “The least that must go into each jar on payday. {name} can add more, never less.” Two of the three jars can carry a floor, Save and Give, each set in steps of 5 percentage points, anywhere from 0 up to 100. Spend never gets a floor of its own. Spend is defined as whatever is left once Save and Give have taken their share, which is also why Save and Give together cannot add up to more than 100%. If they did, there would be nothing left for Spend to be.

Payday, step by step

A payday moves a kid through three screens, always in this order.

First, a ticket. The kid sees what they earned, broken into an “Allowance” line and a “Chore” line for each chore that paid out that period.

Second, a split. The kid decides where the total goes. This screen carries its own plain-English version of “floor”: “The dotted lines are set by a grown-up. You can add more above a line, never less.” The dotted lines mark the floors on the screen; everything above a line is the kid’s to move around, jar to jar.

Third, the landing. The money drops into the three jars in whatever shares the kid chose, or at the floors if the kid left the split alone, and the kid moves on with three updated balances.

A worked example

Say the payday is $10, with a 20% Save floor and a 10% Give floor. At least $2 has to go to Save and at least $1 to Give, no matter what. That leaves $7 that is entirely the kid’s call. They could put all of it into Spend, split it between Spend and Save, or add more to Give than the floor requires. What they cannot do is take Save or Give below its floor, or pull the $3 the floors require out of the total before deciding what to do with the rest.

Why the kid places the rest

The floors are not the kid’s decision. A grown-up sets them once, based on what the household wants a kid saving and giving no matter what else is going on that week. The remainder is the only piece that is genuinely the kid’s choice, payday after payday. That split is not an oversight in the design. It is the one part of the system built specifically to be a small, repeated decision a kid gets to practice on real money. Floors protect the outcome the household cares about. The remainder is where the kid learns to want something and figure out how to get there.