Jake has 773 baseball cards in his colliction naomi has 1215 in hers how many more cards does jake need to collect in order to have the same nuber as naomi
Asked By Jayleen On 02/08/2017 21:45
Let Jake be J and Naomi be N. If J=773 and N=1215, then we are looking to see what value of cards (C) gives us J + C=N. If we plug in the values we get 773+C=1215. Now, let's get C to it's own side by subtracting 773 from each side. This gives us C=1215-773. If we finish the subtraction the answer will be 442 more cards.
Answered On 02/08/2017 21:50
You could solve this problem in many different ways. I will give three common ways for elementary students. If we're trying to find the number of cards Jake needs to have the same as Naomi, we'll call this unknown "x." You could first subtract 1215 - 773 = x using the traditional method of subtraction.Start in the ones place and subtract 5 - 3 = 2. Next, move to the tens place; however, 10-70 isn't possible (without getting a negative number), so we'll "borrow" 100 from the 100s place (leaving 1 hundred) making 110 - 70 = 40. Moving to the hundreds place, we have 100 - 700 which again isn't possible (without getting a negative number), so we'll "borrow" from the 1000s place (leaving 0 thousands). 1100 - 700 = 400. So the final answer is 1215 - 773 = 442 cards. Jake needs 442 cards to have the same amount as Naomi.
The second way this could be solved is using the "counting up" method. The number sentence would be 773 + x = 1215. There are many ways to use this method, but I will demonstrate one way:
First, start with 773 to "add or count up" to 1215. Try to make numbers that end in zero to make the process easier.
I know that 773 + 7 = 780.
Then 780 + 20 = 800
Then 800 + 200 = 1000
Then 1000 + 215 = 1215
Finally, add up all of the amounts to get the final answer: 7 + 20 + 200 + 215 = 442 cards
So the final answer is x = 442 because 773 + 442 = 1215. Jake needs 442 cards to have the same amount as Naomi.
A final way to solve this problem is to use the "Partial Differences" method of subtraction.
With this method, you always subtract starting with the highest place value. In this problem, you would first subtract the thousands place: 1000 - 0 = 1000.
Then, move to the hundreds place: 200 - 700 = -500
Then move to the tens place: 10 - 70 = -60
Then move to the ones place: 5 - 3 = 2.
Finally, add all of the differences: 1000 + -500 + -60 + 2 = 442 Jake needs 442 cards to have the same amount as Naomi.
Answered On 02/12/2017 10:21