A dime has the same value as 10 pennies and a nickel has the same value as 5 pennies. How many pennies will Grace have by exchanging her 10 dimes and 10 nickels?
Grace will have 10 x 10 = <<10*10=100>>100 pennies from her dimes.
She will have 10 x 5 = <<10*5=50>>50 pennies from her nickels.
Therefore, she will have a total of 100 + 50 = <<100+50=150>>150 pennies.
#### 150