Squaring Numbers Ending in Five

The video tutorial explains a simple trick to square numbers ending in five. First, add one to the number in front of the five, then multiply the result by the original number in front of the five. Finally, append 25 to the result. For example, to square 15, add 1 to 1 to get 2, multiply 2 by 1 to get 2, and append 25 to get 225. Another example is squaring 305: add 1 to 30 to get 31, multiply 31 by 30 to get 930, and append 25 to get 93025. This method simplifies squaring numbers ending in five.

What is the first step in squaring a number ending in five using the trick?

• Multiply the number by five

• Add one to the number in front of five

• Divide the number by five

• Subtract one from the number in front of five

Tags

CCSS.6.EE.A.1

After adding one to the number in front of five, what is the next step in the trick?

• Add five to the result

• Square the number

• Multiply the result by the original number

• Subtract five from the result

Tags

CCSS.6.EE.A.1

What is the result of squaring 15 using the trick?

• 200

• 215

• 225

• 235

Tags

CCSS.4.NBT.B.5

In the example of squaring 305, what is the result of multiplying 31 by 30?

• 930000

• 93000

• 9300

• 930

What is the final result of squaring 305 using the trick?

• 93025

• 93125

• 93250

• 93050