these are square root problems.
if you have a scientific calculator,then use it in the future, because it helps.
1. sqrt of 4=2X2=4.
2. the sqrt of 12 and 6 is a long decimal, so it is shortened. 3.46X2.44=8.4424
3. 2.64-1 =1.64
4. 3/1.41=2.12
Hope this helps!
