**The Main Challenge**

Here’s a number trail involving 12 arithmetical steps.

Start with the number **21**, then:

- 1/3 of this
- multiply by seven
- +23
- ÷3
- +75%
- +5
- –7
- Find 10% of this
- Square this
- +2
- Double this
- Square root of this

What is your final answer?

**The 7puzzle Challenge**

The playing board of **the 7puzzle game** is a 7-by-7 grid containing 49 different numbers, ranging from **2 **up to **84**.

The 4th & 6th columns contain the following fourteen numbers:

3 6 7 20 30 36 40 42 49 54 63 64 72 77

Which two numbers, when 10 is added to them, both become square numbers?

**T****he Factors Challenge**

**The Mathematically Possible Challenge**

Using **2**, **9** and **12 **once each, with + – × ÷ available, which are the only TWO numbers it is possible to make from the list below?

10 20 30 40 50 60 70 80 90 100

#*10TimesTable*

**The Target Challenge**

Can you arrive at **338** by inserting **2**, **3**, **4**, **6** and **7** into the gaps below?

- ((◯+◯)³+(◯×◯))÷◯ = 338

**Answers **can be found **here**.

**Click Paul Godding for details of online maths tuition.**