Using the distributive law of multiplication over subtraction

For example:

• 7 × 99 = 7 × (100 − 1) = 700 − 7 = 693
• 7 × 98 = 7 × (100 − 2) = 700 − 14 = 686

Using the right distributive law of division over addition and subtraction

For example:

• 510 ÷ 5 = 500 ÷ 5 + 10 ÷ 5 = 100 + 2 = 102
• 819 ÷ 9 = 810 ÷ 9 + 9 ÷ 9 = 90 + 1 = 91

We can divide numbers that are close to a known multiple of the divisor. For example:

• 7010 ÷ 7 = 7000 ÷ 7 + 10 ÷ 7 = 1000 + 10 ÷ 7 = 1001 rem 3
• 5988 ÷ 6 = 6000 ÷ 6 − 12 ÷ 6 = 1000 − 2 = 998