Holy Crap! Third Grade Math

[allie&mattsmom]

Okay, I just spent a good chunk of my night trying to help my DS (8) with his math homework but one specific problem really had me stumped. DH, the math expert, was golfing again, GRRRR . I even had to call my mom and finally we figured it out together over the phone (we did have a good laugh about how we are itellectually challenged ). Now granted, math was never my strong subject, but I just couldn't grasp this problem. Here it is:

Ben has 20 coins. They are all quarters, dimes, or nickels. What is the greatest amount of money Ben could have if seven are nickels? What is the smallest amount if three are quarters?

Now it seems so simple but for whatever reason I just couldn't get it at the time. After I finally figured it out and I had a major "brain ache" I asked DS if they had an extra desk in his class for me, he thought I was serious and said he'd ask Miss Hogan tomorrow. Oh no, no way am I going back to third grade!!! I might not pass!!! BTW, If anyone figures this out right away, go easy on me, pretty please?

 

[LadyyRedd]

Is it 3.45 and 1.65? That's assuming you have to have at least one of each type of coin. If you don't have to have at least one of each type, then I say 3.60 and 1.60.

Kimya

 

[DisneyAddict_M]

I've always hated word problems.

 

[cotomom]

I hear you! I can't believe what they're doing in my kids' classes (1st and 3rd) ... Let alone hearing that my friends dd in private school (1st grade) will be doing multiplication by the holidays!

 

[allie&mattsmom]

Oops, I got 3.95 & 1.65. I better go recheck it. Stupid math

 

[tiggerlover]

Just wait until 4th grade! DS brought home his geometry homework last night and I was looking at it like it was a foreign language! Parrallewho's???? LOL.

 

[LadyyRedd]

7 nickels = .35
1 dime = .10
12 quarters = 3.00

That's how I did it. I hope I'm right or else i'm just messing you up!

Kimya

 

[allie&mattsmom]

Is it 3.45 and 1.65? That's assuming you have to have at least one of each type of coin. If you don't have to have at least one of each type, then I say 3.60 and 1.60.

Kimya

Yes!! You're right. I thought I had 3.95 but DS's 4 looked like a 9. Whewww. I was really starting to worry about myself. Wow, LadyRedd, you came up with that fast!

 

[Boston Tea Party]

What strategies are y'all using? Is he drawing a picture? Making a chart?

 

[LadyyRedd]

Math has always been my strongest subject. I *almost* majored in math, but ended up going for Information Systems. I finished Calculus in 11th grade. I was the captain of my school's math teams in both middle and high school. Yeah, I was a geek - and proud of it!

For the first part - to get the greatest amount, you have to have as many of the highest coin possible.

So nickels 7x.05 = .35
1 dime (to satisfy requirement) = .10
remaining should be quarters 12x.25

Opposite strategy for the 2nd one.

Kimya

 

[2BigKIdz]

Oops, I got 3.95 & 1.65. I better go recheck it. Stupid math

I think this is right. 13 (q) x .25 = 3.25 + (7 (d) x .10) = 3.95
17 (n) x .05 = .85 + (3(q) x .25) = 1.60

The problem reads quarter, dimes OR nickels so I did not include all 3 coins in each equation which is probably wrong

 

[DisneyAddict_M]

I think this is right. 13 (q) x .25 = 3.25 + (7 (d) x .10) = 3.95
17 (n) x .05 = .85 + (3(q) x .25) = 1.60

My brain hurts.

 

[LadyyRedd]

I think this is right. 13 (q) x .25 = 3.25 + (7 (d) x .10) = 3.95
17 (n) x .05 = .85 + (3(q) x .25) = 1.60

In the first one, 7 have to be nickels, not dimes.

It's not clear from the question if there has to be at least one of each type of coin in each solution or if you can, say, leave out dimes to solve.

Kimya

 

[ChrisnSteph]

Don't feel bad! My third grader once had what I thought was a tough word problem too. I couldn't figure it out for the life of me! I ended up calling my dh at work. He just happened to be in an ambulance at the time with a doctor, nurse, and one other medic. He tossed the problem around, and it took a few minutes before everyone figured out the answer. We all had a good laugh about it, but how sad was that?!

 

[MEG&MINNIE]

Yes, I got $3.45 and $1.65 ,too. My DD9 is in 4th Grade this year and I usually help her with her Math word problems...it really helps if you break it down step by step and take it slowly. It does seem overwhelming at times,they are not the simple word problems we used to have in school. Her school uses the "Everyday Math Series" ,I really do like that series and she is learning math in a different way/better way than her older brothers did. I really do enjoy the word problems !!!

 

[allie&mattsmom]

My brain hurts.

Mine too. DH just came home and said since it says "or nickels" it doesn't mean it would have to be all three quarters, dimes and nickels. He said otherwise it would have been worded "and nickels". OMG, give me a beer.

 

[Beth76]

I got $3.60 and $1.60 and it took me about 30 seconds. Since the problem said "or" I did not use dimes in the equations. I used 7 nickles and 13 quarters since that would give you the greatest amount. In the second I used 3 quarters and 17 nickels since that would give you the least amount.

 

[mcnuss]

OMG - I can totally relate. In 4th grade, DD was doing algebra and in 5th, geometry. I am terrified of what she'll bring home this year in 6th. Everyone's brains are wired differently - that's what I keep telling myself!!

 

[SunFloridaDisney]

7 nickels = .35
1 dime = .10
12 quarters = 3.00

That's how I did it. I hope I'm right or else i'm just messing you up!

Kimya

That's what I figured too

 

[SunFloridaDisney]

OMG, give me a beer.

LOL Hope you don't have to pay for it in nickels