Skip to content
Exit presentation

Power Play

Two powers of one number, multiplied

A box holds 2³ sweets. A carton holds 2⁴ boxes. How many sweets in a carton?

Join the two rows of tiles. Count them. Then write one power.

Loading lab…

2³ × 2⁴ — two powers of 2.
Step 1 of 4
  1. 2³ × 2⁴ — two powers of 2.
  2. Opened out: (2×2×2) × (2×2×2×2).
  3. Join the rows into one line: seven 2s.
  4. 2⁷ = 128.

The rule

A carton holds 128 sweets, which is 2⁷.

Two powers of one base multiply by joining their factors. 2³ has three 2s and 2⁴ has four 2s. That makes seven 2s. The counts add. The base stays. 2³ × 2⁴ is 2⁷: 128 sweets.

  • 7³ × 7⁴ = 7⁷. Three 7s and four 7s make seven 7s.
  • q⁵ × q² = q⁷. Here q stands for any number, and 5 + 2 = 7.
  • 10² × 10³ = 10⁵. Here 2 + 3 = 5.

The counts add only when the base is the same. 2³ × 3⁴ has two different bases, 2 and 3.

Jump to lesson

This track

  1. 0 Start here
  2. 1 A short way to write a long multiplication
  3. 2 Two powers of one number, multiplied
  4. 3 Two powers of one number, divided
  5. 4 One power stacked on another
  6. 5 Walking the ladder down to zero
  7. 6 Every column is a power of ten
  8. 7 Writing a number too long to say
  9. 8 Which of two powers is larger
  10. 9 Counts below zero
  11. 10 Writing a very small number
  12. 11 Checkpoint: small powers and small numbers
  13. 12 The big picture
  14. 13 Track quiz

Other tracks