Green ribbon 42 cm − Yellow ribbon 25 cm
Maya has a green ribbon that is forty-two centimeters long. Her yellow ribbon is twenty-five centimeters long. How much longer is the green one?
Let's mark both lengths on a number line. Yellow stops at twenty-five. Green stretches all the way to forty-two.
The gap between them is the difference — that's what we want to find.
To find the difference we subtract: forty-two minus twenty-five.
Start with the ones place. Can we take five away from two?
Two is too small, so we borrow one ten. Four tens becomes three, and two ones becomes twelve.
Now twelve minus five is seven. Write seven in the ones place.
In the tens, three minus two is one. Write one in the tens place.
Forty-two minus twenty-five is seventeen. The green ribbon is seventeen centimeters longer than the yellow one!