---
title: "Rates: cheat sheet"
subtitle: "Number Foundations"
---

# Rates

> The words and methods from this unit, with an example of each.

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**rate**: A rate compares quantities with different units (km per h, $ per kg); a ratio compares the same kind. 1 km/h = 1000 m ÷ 3600 s: divide by 3.6 for m/s.

$$\text{unit rate} = \text{first quantity} \div \text{second quantity}$$

_At 60 km per hour, 2.5 hours matches 150 km_

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:::keep-together

**using a rate**: Write the units in: km ÷ km/h = h. Then check the size makes sense.

$$\text{total} = \text{rate} \times \text{amount} \qquad \text{amount} = \text{total} \div \text{rate}$$

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