Beth yw degolion?

Rhifau degol / Decimal numbers

Mae degolyn yn ffordd o ysgrifennu rhif sydd ddim yn gyfan.

Rhifau ‘rhwng’ rhifau yw rhifau degol. Er enghraifft, mae 10.4 rhwng y rhifau 10 ac 11. Mae’n fwy na 10, ond yn llai nag 11.

Cymer ofal wrth ddarllen gwerthoedd rhifau degol.

Ystyr 4.2 yw 4 a 2 ddegfed.

Ystyr 4.20 yw 4 a 2 ddegfed a 0 canfed. Does dim angen i’r sero olaf fod yno.

Ystyr 4.02 yw 4 a 0 degfed a 2 ganfed.

A decimal is a way of writing numbers that aren't whole.

Decimal numbers are the numbers 'between' numbers. For example, 10.4 is between the numbers 10 and 11. It's more than 10, but less than 11.

Take care when reading the value of decimal numbers.

The meaning of 4.2 is 4 and 2 tenths.

The meaning of 4.20 is 4 and 2 tenths and 0 hundredths. The final zero doesn't need to be there.

The meaning of 4.02 is 4 and 0 tenths and 2 hundredths.