#### Answer

200 nickels are in 1kg of nickels.

#### Work Step by Step

Use ratios and cross multiplication to find the number of nickels. Ratios must use the same units of measure, so note that 1kg=1000g.
$\frac{1\ nickel}{5g}=\frac{x\ nickels}{1000g}$
$(5)(x)=(1)(1000)$
$5x\div5=1000\div5$
$x=200$