Mental Math · Level Up · L1
To multiply two two-digit numbers, split both into tens and ones and form all four products — tens×tens, tens×ones, ones×tens, ones×ones — then add. It's the distributive law applied twice, and it multiplies any pair.
Watch the method
23 × 47 = (20+3)(40+7). Multiply every part by every part: 20×40 + 20×7 + 3×40 + 3×7 = 800 + 140 + 120 + 21 = 1081.
Tens times tens.
Tens times ones.
Ones times tens.
Ones times ones.
Add the four products.
Your turn
Use the method, then check. Stuck? Reveal the steps.
A two-digit times a two-digit is four little products. Keep them in order (tens×tens is the biggest) and add carefully. Nothing here is harder than the times tables.
Why it works
It's a rectangle split into four smaller rectangles whose areas you add.
34 × 26
Tens×tens
30 × 20 = 600.
Crosses
30×6 = 180 and 4×20 = 80.
Ones×ones
4 × 6 = 24.
Add
600 + 180 + 80 + 24 = 884.
23 × 47
Tens×tens
20 × 40 = 800.
Crosses
20×7 = 140 and 3×40 = 120.
Ones×ones
3 × 7 = 21.
Add
800 + 140 + 120 + 21 = 1081.
79 × 83
Tens×tens
70 × 80 = 5600.
Crosses
70×3 = 210 and 9×80 = 720.
Ones×ones
9 × 3 = 27.
Add
5600 + 210 + 720 + 27 = 6557.
Only multiplying tens×tens and ones×ones.
You must also do the two 'cross' products (tens×ones and ones×tens). Miss them and the answer is far too small.
Losing a place value, e.g. treating 20×40 as 80.
20 × 40 = 800, not 80. Keep the zeros.
12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.
t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).23 × 47 = ?
34 × 26 = ?
52 × 31 = ?
18 × 45 = ?
67 × 23 = ?
84 × 36 = ?
56 × 48 = ?
73 × 29 = ?
96 × 47 = ?
88 × 64 = ?
79 × 83 = ?
65 × 58 = ?