198+132=? make a ten or a hundred to add mentally

When rounded to tens, we get 330.

When rounded to hundreds, we get 300.

Step-by-step explanation:

198+132

Rounding to nearest tens.

198 = 200                                  

132 = 130                  

Adding both we get      

Rounding to nearest hundreds.

198 = 200

132 = 100

Adding both we get

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation: