Hello!
First, let's put √7 and √12 in the number line:
Point A is √7 and point B is √12.
Now, let's write the approximate values to three decimals:
√7 ≅ 2.646
√12 ≅ 3.464
Now, let's calculate the difference between them:
√12 - √7
3.464 - 2.646
0.818 is the difference between these two square roots.
You can also write it as 0.8.
