625.
225
There are many ways to figure 2.5x2.5. If the decimals confuse you, remove the decimals and you may insert them at the end. 25x25=625.Remember*: When multiplying vertically, don't insert the decimal...
2.5 + 2.5 = 5 Here's my attempt at showing the work: 1 2.5 2.5 ---- 5.0
The answer is 50