Coaching Centre
Rates and best buys
Writing rates in simplest form, unit rates, converting rates, solving rate problems and comparing prices to find the best buy.
Unit rates
A rate compares two different quantities. A unit rate is "per one" of the second quantity: $\$12$ for $3$ kg is $\$4$/kg.
Convert $72$ km/h to metres per second.
Best buys
Which is better value: $2$ L of milk for $\$3.20$ or $3$ L for $\$4.65$?
Convert $72$ km/h to m/s.
$72 \div 3.6$.
Better value: $2$ L for $\$3.20$ or $3$ L for $\$4.65$?
$\$1.55$/L vs $\$1.60$/L.
$\$12$ for $3$ kg. Find the price per kg.
$12 \div 3$.
A heart beats $30$ times in $20$ seconds. Find the rate per minute.
$30 \times 3$.
Convert $10$ m/s to km/h.
$10 \times 3.6$.
A worker earns $\$35$ per hour. How much for $15$ hours?
$35 \times 15$.
A tap fills $45$ L in $6$ minutes. Find the rate in L/min.
$45 \div 6$.
Better value: $500$ g for $\$4$ or $750$ g for $\$6.30$?
$\$0.80$ vs $\$0.84$ per $100$ g.
New numbers every time. Keep going until you get five in a row.