Decimal notation — $12.50

Prices in shops use a decimal point: $12.50.

Read it as: twelve dollars and fifty cents (or just "twelve fifty").

The dollar sign goes in front of the number: write $12.50 < / s t r o n g >, n e v er "12.50$ ". Pounds work the same way: £12.50 is twelve pounds and fifty pence.

Why a point?

Because $1 = 100 cents, the two digits after the point are cents:

$12.50 → 12 dollars + 50 cents.

$3.05 → 3 dollars + 5 cents.

$0.99 → 0 dollars + 99 cents (= 99 cents).

The first digit after the point counts tens of cents (dimes), the second counts single cents (pennies). Always two digits.

Watch out — write 0.05, not 0.5

$0.5 < / s t r o n g > w o u l d m e an 50 ce n t s (b ec a u se t h e < s t r o n g > 5 i s in t h e t e n t h s pl a ce < / s t r o n g >) — t ha t^{'} s w h y w e w r i t e i t < s t r o n g >$ 0.50.

$0.05 = 5 cents.

Always write two digits after the point for money.

Cents → dollars

Take whole hundreds out — they become dollars.

250 cents = 2 dollars 50 cents = $2.50.
105 cents = 1 dollar 5 cents = $1.05.
1250 cents = 12 dollars 50 cents = $12.50.

Dollars → cents

Multiply the dollars by 100, then add the cents.

12 dollars 50 cents = 12 × 100 + 50 = 1250 cents.
$3.05 = 3 × 100 + 5 = 305 cents.

Adding decimals

To add $12.50 +$ 3.20, line up the points:

12.50 + 3.20 ------- 15.70 → 15 dollars 70 cents

Try it

🔢 Decimal money

Summary

$12.50 = 12 dollars 50 cents.

Always two digits after the point.

Convert with × 100 (dollars → cents) and ÷ 100 (cents → dollars).

When adding, line up the points.

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