Sharing in a Ratio Flashcards

All 6 cards in this deck

What are the steps to share an amount in a given part : part ratio?
e.g. share $84$ in the ratio $2:5$

1. Add the parts: $2+5=7$
2. Divide to find one part: $84 \div 7 = 12$
3. Multiply each part: $24$ and $60$

How do you find a share when the ratio is given as part : whole?
e.g. red counters : all counters $= 3:8$ in a bag of $40$ counters

Multiply the total by that part over the whole.
$\frac{3}{8} \times 40 = 15$ red counters

How do you find the total when one share is known?
e.g. an amount is shared $3:4$ and the larger share is $20$

Divide the known share by its number of parts, then multiply by the total number of parts.
$20 \div 4 = 5$, $5 \times 7 = 35$

What are the steps to find the shares when the difference between them is known?
e.g. money shared $2:5$, one person gets £24 more

1. Difference in parts: $5-2=3$
2. One part: $£24 \div 3 = £8$
3. Shares: $£16$ and $£40$

True or false? If counters are in the ratio red : blue $= 1:2$, then half of the counters are red.

False. There are $1+2=3$ parts, so $\frac{1}{3}$ are red and $\frac{2}{3}$ are blue.

True or false? To divide $120$ in the ratio $3:5$ you work out $120 \div 3$ and $120 \div 5$.

False. You divide by the total number of parts ($3+5=8$), then multiply by $3$ and by $5$.