Answering Ipad calls on Iphone

I just bought an IPad that can have a sim in it (phone number). I put my second phone number in it.

I was wondering if it is possible when I receive a phone call on my iPad to answer this call on my iPhone?

I agree with Johnathan. That SIM card is used for data access only. You can't receive phone calls on your iPad. Try it, call that phone number assigned to your iPad SIM card. It goes nowhere.

You can pair your iPhone and iPad to work together so you can make and receive calls on the iPad. Callers have to call your iPhone number (instead of the iPad phone number). You can also send/receive SMS text messages on your iPad if it's paired with your iPhone.

Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch

https://support.apple.com/en-us/HT204681

No iPad has a cellular telephone voice modem/radio, so they cannot even connect to any cellular service providers voice network.

An ipad by itself is strictly an internet device - a WiFi & cellular data iPad can connect to the internet via WiFi or over a cellular data network. Thus they are VOIP only devices when it comes to calls (FaceTime, Skype, etc).

When an iPad is paired to an iPhone, the iPad can share calls made from or to the iPhone via a feature of iOS called “continuity”.

iPads cannot receive phone calls.

They do not use the voice channels of cellular services, only data.