Introduction to Ratios Flashcards

All 6 cards in this deck

What does it mean to write a ratio in its simplest form?

Divide every part by their highest common factor, so the parts are whole numbers with no common factor.
e.g. $12:18 = 2:3$

How do you write a ratio in the form $1:n$?
e.g. write $4:10$ in the form $1:n$

Divide both parts by the left-hand part.
$4:10 = 1:2.5$ (here $n$ need not be a whole number)

What are the steps to write a ratio from a worded context and simplify it?
e.g. a bag has 12 red and 18 blue counters; write red : blue

1. Write the amounts in the order named: $12:18$
2. Divide both parts by their HCF ($6$)
3. Answer: $2:3$

How do you express one quantity as a fraction of another?
e.g. express $15$ as a fraction of $12$

Put the first quantity over the second, then simplify.
$\frac{15}{12} = \frac{5}{4}$ (a fraction greater than 1 is fine)

True or false? The ratio $3:5$ means the same as the ratio $5:3$.

False. The order of a ratio matters — it must match the order of the things named.

True or false? Two quantities must be converted to the same unit before writing them as a ratio.

True. Ratios compare like with like.
e.g. $50$ cm $: 2$ m $= 50:200 = 1:4$