how to understand and visualize 0.7X0.7 and (1/4)X(4/5) in terms of repeated addition?
well, since 0.7 = 7 * 0.1,
add up seven times 1/10 of 0.7.
That is, divide the 0.7 into ten equal pieces, and add up 7 of them.
divide 1/4 into 5 equal pieces.
Add up 4 of them.