Let's use this addition problem as an example.

21
35
___

If you have a column of numbers and you go down each column to add them together, that's normal, right?

36
95
15
146

To check to make sure you're right, you'd add from the bottom to the top of each column. If you get the same answer, you know it's right.

15
95
36
146

When my mother was working for her father in the family business (long before calculators or computers) and had to add long columns of numbers, adding down was the standard; then adding up was the double-check.

=)

thank you.

1. 0
2. 5

## Similar Questions

1. ### math

in the addition problems below each leter represents the same digit in both problems. Replace each letter with a different digi, 1-9, so that both addition problems are true.(there are two possible answers.) A B C A D G +D E F +B
2. ### MATH

What are the 3 property names of addition? 1. The Zero Property of Addition- Adding 0 to a number leaves it unchanged. We call 0 the additive identity. 2.Commutative Property of Addition- switching the order of two numbers being
3. ### MATH

What is commutative property of addition? The commutative property of addition says we can change the order of the terms and the result is the same. Thus a+b=b+a. This is one of the field properties of the real numbers. This site
4. ### Chemistry

How do you determine that a certain reagent will result in syn addition, anti addition, or be nonstereospecific? For instance the addition of H2/Pt to a cis-cyclic alkene results in a syn addition. HCl in water is
5. ### chemistry

Hello, im having major issues with this problem...I need to find a pH for a 100.0-mL solution of 0.017 M CH3COOH (Ka = 1.8 10-5) is titrated with 0.025 M NaOH. Now, I've gotten some the answers all ready (right answers have
6. ### chemistry

Hello, im having major issues with this problem...A 100.0-mL solution of 0.017 M CH3COOH (Ka = 1.8 10-5) is titrated with 0.025 M NaOH. Now, I've gotten some the answers all ready (right answers have *)....but three of them are
7. ### math

what are the 5 steps to addition? what are you adding? i know the five steps to division are divide,multiply,subtract,carry,bring down,but I forgot the addition rules.
8. ### Basic Math

I need help adding fractions with different denominators. Here is the problem... 1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 I can see that the demoninators increase. Since they are both addition and subtraction, how do I do this problem?
9. ### math

1. Adding transitions to slides in a presentationâ€¦â€¦ a. Offers effects when moving from one slide to the next ** b. Adds animation to selected text and images c. Adds a new slide to a presentation in Microsoft powerpoint d.
10. ### Ed. tech HELP!!!

When viewing a presentation, words on slides may appear to fly in and out or dissolve. What makes text in a presentation do this? A. The addition of text animations B. The addition of slide transitions C. The addition of Action

More Similar Questions