This may be a bit of a letdown, but there is very little math magic contained in this lesson. For whatever reason, our number sense test writers want us to know our perfect squares. This concept showed up 6 times this year on high school tests--as early as question # 5 and as late as question # 11.
Number Dojo Level: 100
How to Memorize Using Flashcards
Since I was never taught any flashcard techniques, I will share what I have learned through trial and error here. To save you lots of time, I have shared my flashcards on the Worksheets tab of this site. Once you have created the flashcards, follow these steps:
- Isolate the concepts you want to memorize (set the other flashcards aside). I've found that the optimal # to use is 10-25 cards.
- Shuffle the cards thoroughly.
- Time yourself.
- Test your memory. Looking at the front of the top card, say out loud what you think is on the back. Then check your answer. If you are correct, set the card aside in a "Know" pile. If you are incorrect, place this card at the back of the stack in your hand.
- Repeat this process until you are out of cards.
- Stop the timer.
- Record your time.
Thankfully, I have also saved you time by including this concept in my Number Dojo app. If you select Level 100 and hit Drill, it will give you flashcard-style questions until you decide to stop. It also tracks your time and accuracy. You are welcome!
Example 1: 23 x 23 = ___
- You now have this memorized, because you followed the steps above. The answer is 529.
Example 2: 27 x 27 = ___
- You also know this: 729. See a pattern? Not yet? Let's keep trying.
Example 3: 28 x 28 = ___
- The answer is 784.
Example 4: 22 x 22 = ___
- The answer is 484. Getting it? No? A few more:
Example 5: 26 x 26 = ___
- The answer is 676. You are probably catching on...there is a pattern with numbers surrounding (and equidistant from) 25. Their squares end in the same 2 digits! Try 29 & 21 for yourself.