Rounding up in numbers to the nearest whole number and multiple of 5

I'm trying to use the "Roundup" function on a table of costs that include pounds and pence and I am trying to round up to the nearest multiple of £5 and with no pence involved, but for the life of me I cannot get it. I have managed to use roundup to the nearest £1 but I want to roundup to the nearest £5 and with no pence involved. The formula I have used to roundup to the nearest £1 is "Roundup(cell),0". How do I roundup to nearest £5? The table on the left is the original table. The middle one is me using roundup to nearest £1. The table on the right is what I'm trying to achieve with the roundup function. I have just manually typed the figures in the RH table but want it to automatically adjust for subsequent years