Learning Objectives
- 01
Divide by a single digit cleanly with remainders.
Basic Division
1-digit divisors, left-to-right.
Topics
Long division, but mental
Worked Examples
79 ÷ 3=26 r 1
1234 ÷ 5=246 r 4
331 ÷ 5=66 r 1
Estimate, multiply back, subtract the remainder.
- 01
Left-to-right: split into chunks divisible by 5; running quotient
Apply this piece of the shortcut — running quotient 331.
- →
= 66 r 1
Benjamin, Secrets of Mental Math — left-to-right division
212 ÷ 7=30 r 2
Estimate, multiply back, subtract the remainder.
- 01
Left-to-right: split into chunks divisible by 7; running quotient
Apply this piece of the shortcut — running quotient 212.
- →
= 30 r 2
Benjamin, Secrets of Mental Math — left-to-right division
125 ÷ 4=31 r 1
Estimate, multiply back, subtract the remainder.
- 01
Left-to-right: split into chunks divisible by 4; running quotient
Apply this piece of the shortcut — running quotient 125.
- →
= 31 r 1
Benjamin, Secrets of Mental Math — left-to-right division
Talking Points
- •Subtract the largest multiple at each step.
Week 4 · Division & Estimation
Mental division, overshooting, and guesstimation.
- →Mental division
- →Overshooting methods
- →Guesstimation
Sample Problems · Week 4
One simple and one intermediate problem to preview the week.
Simple · Day 1
79 ÷ 3=26 r 1
Intermediate · Day 5
8.25% tax on $47=≈ $3.88