(1) Assuming that all coins in 145 are one yuan, the total amount of money should be 145 yuan, but actually only 127 yuan. Why? Because we also count 50 cents as 1 yuan. 5 jiao =0.5 yuan 1 yuan, more than 0.5 yuan, 0.5 yuan.

So how many nickels are there?

Formula: (145- 127)/0.5 is 1 yuan, which is 0.5 more than that of 0.5 yuan, and the price difference is 0.5.

= 18÷0.5

=36 (pieces)

1 yuan coin: 145-36= 109.

(2) Assuming that all coins in 145 are 50 cents, the total amount of money should be 72.5 yuan, but there is actually 127 yuan. Why? Because we count 1 yuan coins as 50 cents. 5 jiao =0.5 yuan 1 yuan, more than 0.5 yuan, 0.5 yuan.

So how many 1 yuan coins are there?

Formula: (127-72.5)/0.5 is 1 yuan, which is 0.5 more than 0.5 yuan, and the price difference is 0.5.

=54.5÷0.5

= 109 (piece)

Answer: lin li has 109 one-dollar coins in his piggy bank.