9 × 9 = 81
9 multiplied by 9 equals 81
This shows 9 columns × 9 rows = 81 circles in total
Each row has 9 circles, and there are 9 rows
9 × 9 = 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 = 81
Adding row 1 of 9...
Additional information how to quickly calculate this multiplication:
- Hand method:
For numbers between 5 and 10, you can use this special method (this looks easier when visualized using palms, I will explain it later):
9 × 9 = ((9-5) + (9-5)) × 10 + (10-9) × (10-9)
= ((4 + 4) × 10) + (1 × 1)
= (8 × 10) + 1
= 81 - Plus method:
If you know 9 × 8 = 72, then 9 × 9 = 72 + 9 = 81 - Minus method:
If you know 9 × 10 = 90, then 9 × 9 = 90 - 9 = 81