Change into grams.

$2 \mathrm{kg}=$  $\mathrm{g}$

Change into kilograms.

_____ $\mathrm{kg}=$$3000 \mathrm{g}$

Change into grams.

$15 \mathrm{kg}=$_____ $\mathrm{g}$

Change into grams.

$23 \mathrm{kg}=$_____ $\mathrm{g}$

Add:

$\underset{¯}{\begin{array}{cccccc}& \mathrm{kg}& & & \mathrm{g}& \\ & 3& & 2& 1& 5\\ +& 4& & 1& 6& 3\\ & & & & & \end{array}}$ 

Add:

$\underset{¯}{\begin{array}{cccccc}& \mathrm{kg}& & & \mathrm{g}& \\ & 6& & 5& 2& 5\\ +& 2& & 3& 6& 3\\ & & & & & \end{array}}$ 

Add:

$\underset{¯}{\begin{array}{cccccc}& \mathrm{kg}& & & \mathrm{g}& \\ & 7& & 2& 5& 5\\ +& 2& & 1& 6& 3\\ & & & & & \end{array}}$

Subtract.

$\underset{¯}{\begin{array}{ccccccc}& \mathrm{kg}& & & & \mathrm{g}& \\ & 4& 3& & 6& 5& 0\\ -& 1& 1& & 3& 4& 0\\ & & & & & & \end{array}}$

Subtract.

$\underset{¯}{\begin{array}{ccccccc}& \mathrm{kg}& & & & \mathrm{g}& \\ & 2& 6& & 7& 5& 4\\ -& 2& 0& & 3& 3& 0\\ & & & & & & \end{array}}$