adding several numbers

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Gini and Karl help at the Penguin Café ☕: Adding several numbers

The Penguin Café was extra busy this week.
Tourists ordered hot cocoa, iced fish smoothies, and even triple-sardine specials.

Chef Pebble looked at a long sheet of paper covered in numbers and sighed. "So many payments... I hope no fish coins went missing."

Gini and Karl waddled over.

"Don't worry," said Gini. "We'll add everything carefully."

Each row on the paper showed the money the café earned at different times during the week. To keep things tidy, Gini lined the numbers up in columns.

Karl pointed to the rightmost column.
"We always start adding from the right - that's how penguins stay organized."

They added the numbers column by column, starting on the right:

6 + 4 + 5 + 1 + 8 + 4 + 7 + 5 = 40

9 + 2 + 8 + 5 + 2 + 5 + 4 + 2 = 37

8 + 9 + 7 + 7 + 9 + 2 + 4 = 46

7 + 3 + 1 + 6 + 9 + 1 = 27

4 + 8 + 4 + 2 = 18

Whenever the total was more than 9, the extra tens slid over to the next column — just like passing a tray of hot cocoa along the counter.

"Now," said Karl, "we can write the sums under the columns and do all the carry-overs..."

"...or add the column totals together to double-check," Gini added.
"That way we know the café's money count is correct."

Chef Pebble smiled. "Excellent! It's good practice to check both ways. Penguins run on fish and accuracy."

Before closing the café, Gini shared a helpful trick:
"When adding many numbers, look for pairs that make 10, like 6 + 4 or 5 + 5. That makes the rest much easier."

With the money counted and no fish coins missing, the Penguin Café closed for the night — another successful day, perfectly added up.

Example:

	4	7	8	9	6
	8	3	9	2	4
		1	7	8	5
	4	6	7	5	1
			9	2	8
				5	4
		9	2	4	7
	2	1	4	2	5
-	-	-	-	-	-
2	3	5	4	4	-
2	1	2	0	1	0

We add the first column from the right, then the next etc. and then add them together:
6+4+5+1+8+4+7+5=40
9+2+8+5+2+5+4+2=37
8+9+7+7+9+2+4=46
7+3+1+6+9+1=27
4+8+4+2=18
Now we can write them under the columns like above and do all the carry overs or we add those sums together:

				4	0
			3	7
		4	6
	2	7
1	8
-	-	-	-	-	-
1	1	1	1
2	1	2	0	1	0

It's good practise to do both to see if one has made a mistake.
To add several numbers like 6+4+5+1+8+4+7+5=40
you look for numbers that make 10 together like 6+4 and 5+5 in this example, then you only need to add 1+8+4+7, this makes the calculations a bit easier.