Sut i dalgrynnu rhifau degol

Ffocws dysgu

Dysga amcangyfrif drwy dalgrynnu i’r 10, y 100, y 1000 neu’r rhif cyfan agosaf.

Mae'r wers hon yn cynnwys:

• un fideo
• un gweithgaredd

Learning focus

Learn to estimate by rounding to the nearest 10, 100, 1000 or whole number.

This lesson includes:

• one video
• one activity

Fideo / Video

Gwylia Jerry ac Albert yn talgrynnu rhifau wrth fynd i siopa. Faint o arian fydd angen arnyn nhw?

Watch Jerry and Albert rounding numbers whilst shopping. How much money will they need?

Nodiadau i rieni

Wrth dalgrynnu i’r bunt agosaf, rhaid edrych ar y ceiniogau.

• Os yw'n fwy na 50c, talgrynna i fyny i’r bunt nesaf.
• Os yw'n llai na 50c, cadwa’r punnoedd yr un peth.
• Os yw’r ceiniogau yn 50c yn union (sef hanner ffordd), rhaid talgrynnu i fyny.

Wrth dalgrynnu i’r 50c agosaf, rhaid edrych ar nifer y ceiniogau.

• Os yw'n fwy na 25c, talgrynna i fyny.
• Os yw'n llai na 25c, talgrynna i lawr.
• Os yw'n 25c yn union, talgrynna i fyny.

Notes for parents

When rounding to the nearest pound, look at how many pennies there are.

• If the amount is more than 50p, you round up to the next pound.
• If the amount is less than 50p, you round down and keep the pound amount the same.
• If there is 50p exactly (which is halfway), you always round up.

When rounding to the nearest 50p, look at the pennies you have.

• If the amount is more than 25p, round up to the next pound.
• If the amount is less than 25p, keep the pounds amount the same.
• If the amount is 25p exactly (halfway between 0 and 50p), always round up.

Talgrynnu arian neu ddegolion

Mae talgrynnu pris i’r bunt agosaf yr un peth â thalgrynnu degolyn i’r rhif cyfan agosaf.

Os mai £2.80 yw’r pris, gelli di dalgrynnu i fyny i £3 achos mai 8 yw’r rhif yn safle’r degfedau. Y rhif cyfan agosaf at 2.8 yw 3.

Os mai £2.08 yw’r pris, gelli di dalgrynnu i lawr i £2 achos mai 0 yw’r rhif yn safle’r degfedau. Y rhif cyfan agosaf at 2.08 yw 2.

Cofia, os mai 5 yw’r rhif rwyt ti’n ei dalgrynnu, talgrynna i fyny. Mae £2.50 wedi’i dalgrynnu i’r bunt agosaf yn £3.

Rounding money or decimals

Rounding a price to the nearest pound is the same as rounding a decimal to the closest whole number.

If the price is £2.80 you can round up to £3 because the number in the tenths position is 8. The closest whole number to 2.8 is 3.

If the price is £2.08 you can round down to £2 because the number in the tenths position is 0. The closest whole number to 2.08 is 2.

Don't forget, if the number you are rounding is 5, round up. £2.50 rounded to the nearest pound is £3.

Gweithgaredd / Activity

Helpa Jerry ac Albert gyda’u rhestr siopa drwy dalgrynnu’r prisiau hyn i’r rhif cyfan agosaf.

Help Jerry and Albert with their shopping list by rounding these prices to the nearest whole number.