**Elementary School Number Sense Lesson 31: Squaring a Number Just above 50**

This concept appeared just

**1 time**this year--at

**question # 73**.

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Before getting into the regular process, I want to show the “long way” to solve these problems. Let’s try squaring 56 using the FOIL method: (50 + 6)(50 + 6)

**F**: 50 x 50 =**2500****O**: 50 x 6 =**300****I**: 6 x 50 =**300****L**: 6 x 6 =**36**- 2500 + 300 + 300 + 36 =
**3136**

You’ll notice a few things:

- The O & I portion of FOIL are the same.
- If you subtract 50 from the original number, you get
**6**. The last 2 digits are 62 =**36**. - If you add that
**6**to 25, you get the first 2 digits:**31**

**So, here’s how you solve these:**

- Square the units digit and write it down as a 2-digit number.
- Add the units digit to 25 and write the sum in front.

**Example 1: 58 x 58 = ___**

- Square the units digit. 82 =
**64** - Add the units to 25: 25 + 8 =
**33**; write this in front. - Your answer is
**3364**.

**Example 2: 51 x 51 = ___**

- Square the units digit. 12 =
**1**; write this as**01**. - Add the units to 25: 25 + 1 =
**26**; write this in front. - Your answer is
**2601**.

**Example 3: 54 x 54 = ___**

- Square the units digit. 42 =
**16**; write this down. - Add the units to 25: 25 + 4 =
**29**; write this in front. - Your answer is
**2916**.

**Example 4: 59 x 59 = ___**

- Square the units digit. 92 =
**81**; write this down. - Add the units to 25: 25 + 9 =
**34**; write this in front. - Your answer is
**3481**.

**Example 5: 52 x 52 = ___**

- Square the units digit. 22 =
**4**; write this as**04**. - Add the units to 25: 25 + 2 =
**27**; write this in front. - Your answer is
**2704**.

**Here's a free worksheet to help you practice Square51-60:**

square51-60.pdf |

**Up Next for Elementary School: RemainDiv4**