How it works
This multiplication chart 13 runs from 1 × 1 to 13 × 13 = 169. It is the 12 by 12 chart plus 25 new squares, a 13 row and a 13 column, tinted here. Tap any square to tint its row and column.
Read the full guide
What the 13 row adds
13 is a prime number, so none of its multiples appear on a chart that stops at 12. A 13 multiplication chart has 169 squares and 72 different answers, 13 more than the 12 by 12 chart. All 13 sit in the tinted row and column. Counting a fact and its turnaround once, there are 91 facts, up from 78.
Practice and divide with the 13 row
Press New practice chart to empty some squares, type what you know, then press Check to mark every box. To divide by 13, run along the 13 row to your number and read the heading above it. The row reaches 117 under the 9, so 117 ÷ 13 = 9.
- Split 13 into 10 and 3: 13 × 7 is 70 + 21 = 91.
- The ones digits of the 13 row run 3, 6, 9, 2, 5, 8, 1, 4, 7, 0, the same as the 3 row.
- The 13s have meanings: 13 × 2 = 26 letters in the alphabet, 13 × 4 = 52 cards in a deck, 13 × 7 = 91 days in 13 weeks.
Questions and answers
Is 13 × 13 on a regular multiplication chart?
No. A regular chart stops at 12 × 12 = 144. Here 13 × 13 = 169 is the bottom right corner, and 169 appears nowhere else: 13 is prime, and a square on the diagonal has no turnaround.
Why do the 13s light up only 2 squares each?
Because 13 is prime. No other pair up to 13 makes 78, so tapping 78 lights 2 squares: row 13, column 6, and its turnaround. Compare 12 or 24, which each fill 6 squares, the most on this chart.
Is a multiplication chart to 13 a good step past 12?
Yes, because only 13 facts are new, 13 × 1 to 13 × 13. Every other square on a multiplication chart to 13 is already on the 12 by 12 chart.