Lizzy: Judy uses 10 pencils during her 5 day school week. A 30 pack of pencils costs $4. How much will she spend on pencils over 45 days?.
Me: Hmmm, let me think. I think this is the detailed solution:
She uses 2 pencils a day because 10 / 5 = 2. She will use 90 pencils in 45 days because 2 x 45 = 90. She will need 3 packs of pencils because 90 / 30 = 3. She will spend $12 because 3 x 4 = 12. Final answer: 12.