MTC MTC Mental Math Strategies 2

Question 1

Using the 'add one more group' strategy, what is 6 × 9 if you know 6 × 8 = 48?

Accepted Answer

54

Answer

6 × 8 = 48, and adding one more group of 6 gives 48 + 6 = 54.

Question 2

Using the near-ten strategy, what is 11 × 8?

Accepted Answer

88

Answer

10 × 8 = 80, and 80 + 8 = 88, so 11 × 8 = 88.

Question 3

If 7 × 7 = 49, what is 7 × 8 using the 'add one more group' strategy?

Accepted Answer

56

Answer

7 × 7 = 49, and 49 + 7 = 56, so 7 × 8 = 56.

Question 4

Using the near-ten strategy (10 × n − n), what is 9 × 9?

Accepted Answer

81

Answer

10 × 9 = 90, and 90 − 9 = 81, so 9 × 9 = 81.

Question 5

Using doubling twice, what is 8 × 8? (Start with 2 × 8 = 16)

Accepted Answer

64

Answer

2 × 8 = 16 → 4 × 8 = 32 → 8 × 8 = 64 by doubling twice.

MTC - Multiplication Tables Check Practice Test