Here’s an example of a **SPEED MATH** shortcut for **CHECKING SUBTRACTION: (Check) Sub** from the **CHECKING ANSWERS** category.

Make sure to check out **SEED NUMBER CONCEPT** to understand how Seed numbers are calculated.

**When can I use this method?**

For checking any Subtraction.

This method can also be used to check problems with a combination of additions and subtractions also.

[contentblock id=google-adsense-post]

[starrater tpl=10]

[tubepress mode=”playlist” playlistValue=”PL9A327FD3A1C6B6BE”]

** Download Practice sheet for CHECKING SUBTRACTION**

[contentblock id=google-adsense-post]

**Notes –**

- Make sure to check out
**SEED NUMBER CONCEPT**to understand how Seed numbers are calculated. - Any time you come across a seed number values greater than 1-digit, reduce it to a single digit value using the seed number concept.
- Any time you come across a negative (-ve) seed number; add 9 to it to get is positive (+ve) value. Do the same if the seed number is = 0.
- It is the fastest and easiest way to verify your answers.

**Related Shortcuts –**

Checking Division : (Check) Div

Checking Multiplication : (Check) Mul

Checking Addition : (Check) Add

[contentblock id=speedmath-blockquote]

## 2 replies on “[Speed Math] CHECKING SUBTRACTION”

23-18=5

in this 23 has seed no 5 * 18 has seed no 9 if we deduct 5-9 =6, and ans is 5 as seed no. so plz explain me how it came ?

For the seed number concept, 9 is treated as 0, so when you are doing 23-18, the seed numbers are 5-0=5.