Multiplying Decimals Flashcards

Grade 5 · Math · Flashcards

Key rules and practice problems for multiplying decimal numbers.

Flashcards

Rule for multiplying decimals: Multiply as if whole numbers, then count total decimal places in both factors and place the decimal that many spots from the right in the product.
0.4 × 0.7 = ?: 0.28 (4×7=28, 2 decimal places)
0.3 × 0.3 = ?: 0.09 (3×3=9, 2 decimal places → 0.09)
1.5 × 4 = ?: 6.0 (15×4=60, 1 decimal place → 6.0)
0.06 × 0.8 = ?: 0.048 (6×8=48, 3 decimal places → 0.048)
What happens when you multiply a decimal by 10?: The decimal point moves one place to the right (e.g., 0.56 × 10 = 5.6).
What happens when you multiply a decimal by 100?: The decimal point moves two places to the right (e.g., 0.56 × 100 = 56).
2.3 × 1.1 = ?: 2.53 (23×11=253, 2 decimal places → 2.53)
Estimate 3.9 × 5.1: About 20 (round to 4 × 5 = 20; exact = 19.89)