Three digits by two digits

What this lesson shows

312 × 24 with an area model, checked with an estimate.

The worked example

The lesson works this one step by step: 324 × 23. Then your kid tries one like it on paper.

The steps

1. Break both numbers apart
2. Fill six boxes
3. Add the parts
4. Check with an estimate

Helping at home

Break both numbers apart and draw six boxes. Say each box in place value, add the six parts, then check with an estimate.

If your kid gets stuck

Break both numbers apart, then draw six boxes.

Standards

• Common Core 4.NBT.B.5
  Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
• Common Core 5.NBT.B.5
  Fluently multiply multi-digit whole numbers using the standard algorithm.

More in this unit

• Hard facts from easy ones
• Division facts are missing factors
• Multiplying by 10, 100, and 1,000
• Estimating products
• Area model, three digits by one
• Partial products, two digits by two
• The standard algorithm, two digits by two
• The zero in the second row
• Where the carried digit goes