Memorising as many times tables as possible is a good idea if you want to do well in maths, and KS3 Maths is no different. Usually, people learn the times tables up to 12 but we thought you'd like a bit more of a challenge. So we're going to test your times table knowledge all the way up to the 20 times table. In this quiz we look at the 15 times table.

165, 225 and 285 are multiples of 15 and so they are all found in the 15 times table. 15 is a triangular number and one which we come across quite often. Each player has 15 counters at the start of a game of backgammon and there are 15 red balls in a game of snooker. 15 is also an odd number. The Roman natural historian and philosopher, Pliny the Elder, said "Why do we believe that in all matters the odd numbers are more powerful?"

It's all about practise when it comes to memorising the times tables. Have a go at this quiz and see how well you know the 15 times table.

1.

What is 20 x 15

300

305

315

291

2 x 15 = 30 so 20 x 15 = 300

2.

What is 18 x 15

270

280

265

264

20 x 15 = 300 and 2 x 15 = 30 so 300 - 30 = 15 x 18

3.

What is 15 x 15

235

226

234

225

15 is the square root of 225

4.

What is 17 x 15

260

258

250

255

In Roman numerals 255 is written as CCLV

5.

What is 19 x 15

280

276

285

281

20 x 15 = 300 and 300 - 15 = 285

6.

What is 11 x 15

174

168

169

165

10 x 15 = 150 and 150 + 15 = 165

7.

What is 10 x 15

156

155

149

150

To multiply any number by 10 simply put a zero on its end

8.

What is 9 x 15

126

135

125

143

10 x 15 = 150 and 150 - 15 = 135

9.

What is 6 x 15

89

88

90

96

5 x 15 = 75 and 75 + 15 = 90

10.

What is 5 x 15

77

66

75

73

10 x 15 = 150 so halve 150 to find the answer