Help with a 2nd grade math question?

1) 90-30=80-20 80-70=20-10

2) 70-40=60-30 60-10=90-40

You're welcome

I think that the problem here is that there are 2 questions per line

Write the number that makes each number sentece true.

1) 90-30=80-20 or Both equal 60, but the answer is 20

80-70=20-10= 10

2) 70-40=60-30 = 30 60-10=90-40 = 50

I assume there is a space in between

1) 90-30 = 80-20 80-70=20-10

2) 70-40 = 60-30 60-10=90-40

Is this what you meant to put?

1) 90-30=80-__

80-70=20-__

2) 70-40=60-__

60-10=90-__

If so, just make the answers equal on both sides by figuring one side:

90-30=60

..and then figure out what you need to subtract from 80 to make it equal to 60:

80-?=60

80-20=60

I think the problem might be that there are two problems being run together for each numbered problem, rather than just assigning them as separate problems.

So your answer should look like this...

90-30=80-20

The idea is to see that the 80 is 10 less than 90, so the blank must be 10 less than 30. You can solve each of the problems without ever having to actually figure out that 90 - 30 = 60, 70 - 40 = 30, etc.

In this case, understanding that there is a pattern to subtraction is more important than the actual arithmetic.

Obviously, just memorizing math facts like 7-3=4 through rote memorization doesn't make people comfortable enough with numbers to see the obvious patterns that make math a lot easier as you learn new things.

1. 90-30=80-20 80-70=20-10

2. 70-40=60-30 60-10=90-40

OK.

1) 90-30=80-20 (=60) |||| 80-70=20-10 (=10)

2) 70-40=60-30 (=30) |||| 60-10=90-40 (=50)

1) 90-30=80-20

80-70=20-10

2) 70-40=60-30

60-10=90-40

Are you sure this isn't four questions and not two?

I could answer 90-30 = 80 - ???

and 80-70 = 20 - ???

separately, and the answers would be 90-30=60 which is also equal to 80-20

so the answer to the first first question is 20.

Likeways, 80-70=10, and 20-10=10, so the answer to the second first question is 10

Does this make sense?

This is second grade??

I don't know how this can be solved, at first when I saw the q. I thought you were crazy not knowing a second grade q. , but this is weird, I don't get what you have to do!

Oh wait!

70-40=30 right? So 60-30=30, you need to make them equal. 60-10 is 50, so 90-40 -50, you need to get both answers to be the same.

1. 90-30=80-20 80-70=20-10

2.70-40=60-30 60-10=90-40

All it is asking is since 70-40 equals 30, you have to find what makes 60-x=30.