How do you round 3.99 to the nearest tenths?

3.99 = > 3 + 0.99

first let's round up the 0.99, and the 9 rounds up to 1.0  so 0 + 1.0 = 1.

3 + 1 = 4, rounded up.

to the nearest tentth, 4.0.

the .0 simply means 0 tenths, since it's a whole 4.

step-by-step explanation:

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.