Percentages

[plum100]

Hello, can anyone tell me how a year 5 child would be taught to work out simple percentages such as 30% of £2.20?

Dd says shes forgotten but i dont want to confuse her with different ways and terminology. Would she divide 2.20 by 100 then muliply the answer by 30?

Thanks in advance x

She shoul be working this out on paper by the way x

Find 10% then multiply by 3.

So 22p * 3 =66p

Agree with richmal . Find 10% by dividing by 10, then multiply by 3.

However the 'safest' way is to learn from first principles, which is as you said. Find 1% by dividing by 100, then multiply by 30.

Only if they can do the above then learn the shortcuts, and why they work.

After all, percent means by 100 or something, so useful to have the 100 in the calculation.

(Disclaimer - not a teacher)

Thank you x

Plum 100:

agree with method suggested by richmal 10% then multiply by 3 - but the issue may be not understanding effect of multiplying/ dividing by tens (PLACE VALUE).

So first principles:

What happens to 2 when I multiply by 10 - it becomes 20 (In ye olden times - young dinosaurs like myself were told to write down the number you're multiplying 10/ 100/ 1000/ 10000000 by - then count the zeros in the 10/ 100/ 1000/ 10000000 and 'stick' them on the end) -

So once your DC gets

2 x 10 = 20
2 x 100 = 200
2 x 1000 = 2000
2 x 10,000 = 20,0000

you can then start the same game with numbers