6Multiplying decimals
Work out 2.4 × 0.35 without a calculator.
2.4 × 0.35 = 0.84. Multiply the digits ignoring the decimal points (24 × 35 = 840), then place the point so there are 3 decimal places total (1 from 2.4, 2 from 0.35), giving 0.840 = 0.84. A rough check: 2 × 0.4 = 0.8, close to 0.84.