Rate

Practice 3 items →

A rate compares different units; a unit rate has 1 in the denominator. Students compute and compare unit rates and solve combined-work problems by adding rates, never times.

Specification · for a parent or teacher

Part no.: unit-rate-work
Course: Advanced Math 5 · Unit 14
Realm: Applied
Difficulty: 3 of 4 — Grade 6–7 core. Multi-step, first symbolic work.
Qty: 3 items

Part no. is the node's id; the realm is the kind of math; qty is how many practice items it carries.

Students can

unit rates; comparison of rates; combined work (A and B together).

Ready when

“A paints a fence in 6 h, B in 3 h; together?” as $\frac{1}{6}+\frac{1}{3}=\frac{1}{2}$ , so 2 hours.

Formulas

Combined work

\frac{1}{t_A} + \frac{1}{t_B} = \frac{1}{t_{\text{together}}}

Watch for

3/4 of a tank in 2 hours → rate as 3/4 per hour; work problems adding times instead of rates.

Before · requires

Ratioratio-tape-diagrams · Math 5
Fractions as divisionfraction-as-division · Math 5

After · used by

Rate and speedrate-speed · Math 6

Print this set Open on map