15 × 48 in Two Steps? Multiply by 15 Trick, No Carrying | Mental Math for Grades 3–6

Learn to multiply any number by 15 in your head in two steps, with no carrying. The rule: multiply by 10 (add a zero), then add half of that. Example: 15 × 48. Times 10 is 480. Half of 480 is 240. 480 + 240 = 720. Odd numbers work the same way: 15 × 53. Times 10 is 530. Half of 530 is 265 (half of 500 is 250, half of 30 is 15). 530 + 265 = 795. Chapters 0:00 48 packs of 15 stickers: how many? 0:21 The rule 0:28 Example: 15 × 48 0:56 Your turn: 15 × 62 1:16 What about odd numbers? 1:23 15 × 53 1:50 Boss level: 15 × 124 2:15 Your challenge: 15 × 86 2:24 What's next Practice (answers in the pinned comment) 15 × 86 15 × 215 15 × 36 15 × 74 15 × 91 Previous trick: Multiply by 13 →    • Multiply by 13 Fast: Triple-and-Add Trick ...   Next trick: Multiply by 111 → [video 9 link] All tricks in order → [playlist link] Math Sigmas is a weekly mental math channel for kids in grades 2–6, and for anyone training for Math League, Number Sense or MOEMS. New trick every week. #mentalmath #mathtricks #multiplication #mathforkids