Third grade math, what is predict and test?

Question

The sum of two numbers is 39. The difference between the two numbers is 11. what are the two numbers?

Answer 1

you have 2 equations: a+b=39 and a-b=11. if you solve for a using the 2nd equation, you get a=11+b. then you plug that a into the 1st equation to get 11+b+b=39. you subtract 11 from both sides to get 2b=28. then you divide both sides by 2 to get b=14. you then take that and plug it into either equation to get a=25.
hope this helped!

Answer 2

"predict and test" is what the name suggest... you 'predict' (or guess) the 2 numbers and then 'test' if it is true in the question or not....

like for your third grade kid, ask him/her to just guess any two numbers which make 39....
lets say kid says 38 and 1.
sum = 38 + 1 = 39 (true)
BUT
difference is 38-1 = 37 (not true)....

So... let the guessing (predicting continue....).. the guessing may go like..
37&2 -- sum is 39 but difference is 35.... uh oh, difference is still high....

another guess 29 & 10-- sum is 39 but difference is 19..... hmmm... difference is getting close..... so I may keep on guessing another numbers ......

Let the kid do this by themselves.... the exercise helps the kid in doing lot of additions and subtractions...

and finally when the kid does reach to 25 & 14..... and he finds that it matches both the answers.... you can see the satisfaction in his/her face !!!!

Answer 3

Erm... are you asking for the answer or what predict and test is?
Predict and test is trial and error, or guess and check.
To get the answer using predict and test, simply take a guess and see if it works. Repeat until correct answer is reached.
The numbers are 25 and 14.

Answer 4

39=2n+11

(39-11)=2n

28=2n

28/2=n

14=n

14, (14+11)

so 14,25 would be a solution

although i don't think algebra I would be used in 3rd grade

Answer 5

the answer is easily 25 and 14
ugh silly 3rd graders

Answer 6

25 and 14

obvious...