Did you get 1.84? What?  You didn't ... you're telling me it's 18.4!  Well you're right ... can't fool you can I!

That's right, the two numbers were 6.5 and 2.8, so we could round them to 7 and 3 telling us the answer is around 21.

Now in case you didn't get the answer, have a look at how we get the answer ...

1. First, line up C10 with 6.5 on the D scale.
2. Now move the cursor to 2.8 on the C scale.
3. Then read the answer 18.4 below on the D scale.

Now that this is all under control, click here to go back to the lesson.