Question

I need help teaching my 2nd grader how to come up with the answer. Easy for an adult..difficult to explain to a child.

I am thinking of 2 numbers who sum is 15.
One of the numbers is 9 more than the other. Got the 12 plus 3 part. Help me explain it in its simplest terms

Answer 1

I'd use counters -- like M & Ms or pennies.

Answer 2

That is my thought but how do I pose the question? I took a deck of cards for counters and tried to figure out how to go about it.

Answer 3

THANK YOU by the way!

Answer 4

Put out 15 objects.

Then have your child take 9 of them away.

How many are left?

Answer 5

that's not the answer. its how to get her to 12 is 9 more than 3 that equals 15

Answer 6

start with your 15 objects
take 1 away, the pile left is 14 more than what she took away, and 14-1=13
take 2 away, the pile left is 13 more than what she took away, and 13-2=11
take 3 away, the pile left is 12 more than what she took away, and 12-3=9

ahhh, one is 3, the other is 12


for yourself:

x+y = 15
x-y = 9
add them
2x = 24
x=12 , then y = 3