Eights are double fours
7 × 8 is double 7 × 4. That is double 28, which is 56.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Nines are tens minus one group
7 × 9 is 7 × 10 take away one 7: 70 − 7 = 63.
A pattern in the nines
The digits of every answer add to 9. 63 gives 6 + 3 = 9. So does 27, and 45.
That pattern is a good check, not a way to work the answer out.
Eights are doubles of doubles
6 × 8 can be built by doubling three times: 6 × 2 = 12, doubled is 24, doubled again is 48. Since 8 is 2 × 2 × 2, doubling three times gets you there. Some children find this faster than recall, and it always works.
The nines pattern
In the 9 times table the tens digit goes up by one and the ones digit goes down by one: 09, 18, 27, 36, 45, 54, 63, 72, 81, 90. And the two digits of every answer add to 9. Both patterns have the same cause — nine is one less than ten.
Nines from tens
7 × 9 is 7 × 10 = 70 minus one group of 7, giving 63. That is where the pattern comes from: every step of nine is a step of ten with one taken back. Understanding the reason means the pattern will not desert you when you are under pressure.
Step 2: Try It Yourself
Tap and try it out.
7 × 9 = 63
7 × 9 = (7 × 5) + (7 × 4) = 35 + 28 = 63
The array is cut into 7 × 5 and 7 × 4. Two easier facts that add to the same total.
Step 3: Watch an Example
One step at a time.
Watch Leo Use the Tens
Leo is asked for 8 × 9.
- Step 1
He works out 8 × 10 first, which is 80.
Step 4: Your Turn
Practice makes it stick.
The Spiders
Problem 1 of 2
6 spiders each have 8 legs. How many legs?
legs
The Rows
Problem 2 of 2
9 rows of 9 chairs. How many chairs?
chairs
Eights and Nines
1 of 4
4 × 8 = ?
2 of 4
8 × 8 = ?
3 of 4
6 × 9 = ?
4 of 4
72 ÷ 8 = ?
Step 5: Quick Check
Show what you know.
Question 1 of 2
7 × 9 = ?
Question 2 of 2
In the nine times table, what do the digits of each answer add to?
What You Learned
- Eights are double fours.
- Nines are tens with one group taken away.
- The digits of every nine answer add to 9.