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 the amount by the total parts: $84\div7=12$
3. Multiply: shares are $2\times12=24$ and $5\times12=60$

True or false? To share £60 in the ratio $1 : 3$ you divide £60 by 3.

False.

You divide by the total number of parts, $1+3=4$.

How do you find each part when you are given a part : whole ratio?

e.g. blue : total $= 3 : 5$ for 40 counters

Use the part over the whole as a fraction of the amount.

Blue $=\frac{3}{5}\times40=24$, so the rest is $40-24=16$.

How do you find the total when you know one share and the ratio?

e.g. ratio $3 : 5$ and the smaller share is 12

Divide the share by its number of parts, then multiply by the total parts.

$12\div3=4$ per part, total $=4\times8=32$.

How do you find the other share when you know one share and the ratio?

e.g. $A : B = 2 : 7$ and $A = 6$

Find the value of one part, then multiply by the other number of parts.

$6\div2=3$ per part, so $B=7\times3=21$.

How do you express the division of a quantity into two parts as a ratio?

e.g. 20 sweets split into 15 and 5

Write the two parts in the order asked, then simplify.

$15 : 5 = 3 : 1$