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Extended multiplication table from 1 to 20

The extended multiplication table is a Pythagoras table in which the intersection of a row and a column contains the product of the corresponding numbers. Unlike the basic table up to 10, the extended version covers numbers from 1 to 20 and allows you to calculate in your head faster, solve problems in algebra and geometry, and save time on exams.

The table is useful for schoolchildren, students, and anyone who wants to maintain their mental arithmetic skills. It is especially helpful when working with fractions, percentages, and areas, where products of two-digit numbers are common.

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How to read the table

Find the first number in the left column and the second in the top row. At the intersection of the row and column is their product. For example, 7 × 8 = 56. The diagonal is highlighted in gray — these are the squares of numbers (1, 4, 9, 16, … 400).

Pythagoras table from 1 to 20

× 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
2 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
3 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60
4 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80
5 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
7 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 112 119 126 133 140
8 8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160
9 9 18 27 36 45 54 63 72 81 90 99 108 117 126 135 144 153 162 171 180
10 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200
11 11 22 33 44 55 66 77 88 99 110 121 132 143 154 165 176 187 198 209 220
12 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240
13 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 208 221 234 247 260
14 14 28 42 56 70 84 98 112 126 140 154 168 182 196 210 224 238 252 266 280
15 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300
16 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 272 288 304 320
17 17 34 51 68 85 102 119 136 153 170 187 204 221 238 255 272 289 306 323 340
18 18 36 54 72 90 108 126 144 162 180 198 216 234 252 270 288 306 324 342 360
19 19 38 57 76 95 114 133 152 171 190 209 228 247 266 285 304 323 342 361 380
20 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400

Example: at the intersection of row 12 and column 15 is the number 180 — this means that 12 × 15 = 180.

How it differs from the table up to 10

The basic multiplication table covers numbers from 1 to 10 and is studied in primary school. The extended one covers 1 to 20; it is not part of the compulsory curriculum but is useful for calculation speed and solving more complex problems.

Characteristic Up to 10 Up to 20
Range of numbers1–101–20
Number of examples100400
Grade levelPrimary schoolMiddle school, for speed
ApplicationFoundation of calculationFractions, percentages, areas

If you haven't yet mastered the basic table, start with it: Multiplication table from 1 to 10.

Why the extended multiplication table is needed

  • It allows you to quickly calculate products of two-digit numbers in your head.
  • It speeds up solving problems in algebra, geometry, and physics.
  • It helps when working with fractions, percentages, areas, and volumes.
  • It saves time on exams and tests.
  • It trains memory and develops mathematical thinking.

How to memorize the extended table

The basic principles are the same as for the basic table. The full guide is on the page "How to learn the multiplication table quickly". In brief: «How to learn the multiplication table quickly».

  1. Use the commutative law: 12 × 15 = 15 × 12. This halves the amount of memorization.
  2. Rely on "anchor" examples: 10 × 10 = 100, 10 × 20 = 200, 20 × 20 = 400.
  3. Break complex examples into simple ones: 12 × 15 = (10 × 15) + (2 × 15) = 150 + 30 = 180.
  4. Practice regularly for 10–15 minutes a day on the online trainer.

Frequently asked questions about the extended multiplication table

Why is the multiplication table up to 20 needed?

The multiplication table up to 20 helps you calculate in your head faster, solve problems in algebra and geometry, and saves time on exams. It is especially useful when working with fractions, percentages, and areas.

Do you need to learn the multiplication table up to 20 at school?

Only the table up to 10 is part of the compulsory curriculum. The table up to 20 is optional but useful for quick mental calculation and solving problems in middle school.

How can I memorize the table up to 20 quickly?

First, learn the basic table up to 10. Then rely on anchor examples (10 × 10, 10 × 20, 20 × 20) and break complex examples into simple ones: 12 × 15 = (10 × 15) + (2 × 15). Practice regularly.

Compiled by: Alexey Pavlov, mathematics teacher.
Source: classic Pythagoras table in extended form.
Last updated: 11.10.2026.

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