think about the mathematical process you use as you solve the following problems. show your work.
a. If there are 100 students in a room and 40 of them are boys, how many are girls?
b. if there are 17 blue and white stripes on the flag and 9 of them are blue, how many are white?
c. if there are 250 pennies and dimes in a box and 130 of them are pennies, How many are dimes?
d. now it is time to generalize. Imagine you know how many items you have in a collection of two types of things. If you know how many of one of the items you have,How could you find how many of the other item you have?

Question

think about the mathematical process you use as you solve the following problems. show your work.
a. If there are 100 students in a room and 40 of them are boys, how many are girls?
b. if there are 17 blue and white stripes on the flag and 9 of them are blue, how many are white?
c. if there are 250 pennies and dimes in a box and 130 of them are pennies, How many are dimes?
d. now it is time to generalize. Imagine you know how many items you have in a collection of two types of things. If you know how many of one of the items you have,How could you find how many of the other item you have?

anonymous · Answer

Um can you help me?

vocaloid · Answer

well, let's go one by one: 

a. If there are 100 students in a room and 40 of them are boys, how many are girls?

anonymous · Answer

60 ^w^?

vocaloid · Answer

right, and we got that by subtracting 100-40, correct?

anonymous · Answer

Yes.

vocaloid · Answer

now let's move to the next question:

b. if there are 17 blue and white stripes on the flag and 9 of them are blue, how many are white?

vocaloid · Answer

hint: 17 = blue + white

anonymous · Answer

8?

vocaloid · Answer

right

vocaloid · Answer

c. if there are 250 pennies and dimes in a box and 130 of them are pennies, How many are dimes?

anonymous · Answer

^-^ ok um so 120.. for c?

vocaloid · Answer

right!

now, I'm sure you've noticed the pattern in these problems. question d is asking you about that pattern.

d. now it is time to generalize. Imagine you know how many items you have in a collection of two types of things. If you know how many of one of the items you have,How could you find how many of the other item you have?

vocaloid · Answer

if you know the total, and you know how many of one type you have, then to find the other type, you subtract

total - first type = second type

vocaloid · Answer

that should be a sufficient answer for d)

anonymous · Answer

Thank you. C:
sorry I'm a slow person ._.

vocaloid · Answer

nah, no need to apologize, you actually caught on pretty quickly

anonymous · Answer

:3 ty

anonymous · Answer

@Vocaloid Um can you help me with another question in a few minutes...I'll open a new post. c:

vocaloid · Answer

sure