Mental Math Calculation Tricks

Vocabulary flashcards covering quick mental math shortcuts and calculations from the video lesson.

Trick for Multiplying Two-Digit Numbers by $11$

A mental math technique where you write the tens and unit digits on the ends and place their sum in the middle, carrying $1$ to the left if the sum is $≥ 10$ (e.g., $43 \times 11 = 473$ and $68 \times 11 = 748$).

Trick for Multiplying Three-Digit Numbers by $11$

A mental math technique where you keep the outer digits at the ends and place the sum of the first two digits and the sum of the last two digits in the middle, carrying over if any sum exceeds $9$ (e.g., $352 \times 11 = 3872$ and $574 \times 11 = 6314$).

Trick for Multiplying Two-Digit Numbers Ending in $5$ with the Same First Digit

A mental math shortcut where you multiply the tens digit by its next consecutive integer and append $25$ to the end (e.g., $75 \times 75 = 5625$ and $35 \times 35 = 1225$).

Trick for Multiplying Numbers with Same First Digit and Ending Digits Summing to $10$

A mental math technique where you multiply the shared first digit by its next consecutive integer, multiply the two ending digits together, and place the results side by side (e.g., $44 \times 46 = 2024$ and $67 \times 63 = 4221$).

$$86 \times 84$$

A mental math calculation resulting in $7224$, computed by multiplying the tens digit $8$ by $9$ to get $72$ and the unit digits $6 \times 4$ to get $24$.

$$574 \times 11$$

An example calculation of a three-digit number multiplied by $11$ resulting in $6314$, solved by calculating $5 + 7 = 12$ and $7 + 4 = 11$ and applying carries.

Part $2$ Video Threshold

The requirement of obtaining $10000$ likes on the video to produce the next installment of mental math tricks.