Today in Mrs A's maths group, we had to solve the problem of 21 x 15. I used money to solve the strategy. I displayed the money on the floor and I had to put 5 and ten together in 15 rows. I skip counted in 5's and I came to 105. Next I counted in 10's - which came to 210, after this I added 105 + 210 together, and this made 315.