Bill Split Calculator

[Please note first]

This app only works out amounts. It cannot send or collect money.

It keeps no names and no record of who paid what.

There is no price guide, no sales tax, no tipping and no exchange rate.

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÷ Bill Split Calculator — does what you collect add back up to the bill?

The mistake in splitting a bill comes after you work out one share.

Thirteen thousand yen among seven is 1,857 yen and change.

Round to 100 yen and everyone pays 1,800 yen: that raises 12,600 yen and

falls 400 yen short. Everyone paying 1,900 yen raises 13,300 yen, 300 too much.

What this app gives you is the arrangement that fits, and the gap when none does.

■ The remainder vanishes when a few people pay one unit more

13,000 yen among 7, rounded to 100 yen.

Who pays what … 4 × 1,900 yen / 3 × 1,800 yen

Total collected … 13,000 yen

Against the bill … Exact

130 units divided among seven leaves a remainder of 4, so four people pay

100 yen extra. That lands exactly on the bill.

■ When it cannot be exact, the app says so

19,800 yen among 6, rounded to 500 yen.

Who pays what … 3 × 3,500 yen / 3 × 3,000 yen

Total collected … 19,500 yen

Against the bill … 300 yen short

19,800 does not divide by 500, so no arrangement comes out exact. The missing

300 yen has to be made up by whoever collects the money. Saying that in words

rather than showing a bare minus figure is what this app is for.

■ Small units land exactly

23,456 yen among 5, rounded to 1 yen.

Who pays what … 1 × 4,692 yen / 4 × 4,691 yen

Against the bill … Exact

18,000 yen among 4 in 500 yen units gives 4 × 4,500 yen, also exact.

The larger the rounding unit, the more likely a gap.

■ Or the organiser can take the odd change

Everyone else pays the same rounded-down amount and the organiser covers

what is left.

13,000 yen among 7, rounded to 100 yen.

Everyone else … 6 × 1,800 yen

The organiser … 2,200 yen

Adds up to … 10,800 + 2,200 = 13,000 yen

19,800 yen among 6 in 500 yen units gives 5 × 3,000 yen for the others and

4,800 yen for the organiser: 15,000 + 4,800 = 19,800 yen. Because the organiser

absorbs whatever does not divide, this arrangement is always exact.

■ Only three things to enter

▪ The bill total

▪ How many people

▪ What to round each share to (1, 10, 100, 500 or 1,000 yen)

Two of them are typed. The rounding unit is a button.

■ When it comes in handy

▪ Deciding how much to ask each person for after the meal

▪ Checking whether collecting round hundreds still matches the bill

▪ Deciding whether one person absorbs the odd change or everybody shares it

▪ Knowing in advance how much extra the organiser ends up paying

■ Good to know (included in the app)

▪ One share worked out on its own does not add back up to the bill

▪ The remainder disappears when a few people pay one unit more

▪ A larger rounding unit means a wider gap

▪ The organiser method always lands exactly on the bill

■ How the app is built

▪ A single screen. No settings page

▪ Your last five entries are kept and can be tapped to restore

▪ The result copies with one tap

▪ Japanese and English, following your device language

▪ No account needed. Every sum runs on your device and the amounts you type are never sent anywhere

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Note: this app only works out amounts. It cannot send or collect money and has

no QR codes. It keeps no names and no record of who paid what. It has no price

guides, no sales tax, no tipping and no exchange rates, and it offers no advice

on who ought to pay more.

NISAKE GAME