Here are some suggestions about how your child can further explore 20:
We would start off in class encouraging your child to count their set of 10 fingers and then to take their socks off and count their toes. They carry their own 'Part Part Whole' model around with them ALL the time. Help them to see that they always have 20 fingers and toes altogether. Then the fingers are 1 'Part' and the toes are another 'Part'.
If (and ONLY if) your child is secure with the fingers and toes all adding up to 20, they may be ready to attempt counting in 10's using their fingers first - 10, then look at the toes - 20, adult to add in own set of 10 fingers - 30, then toes - 40....and so on. They can learn to recite, counting in 10's up to 100, flashing a set of 10 fingers as they go- but only if you feel they are ready and interested in this!
If 20 seems far too many at this point, please do not worry - simply revisit 10, concentrating on their fingers. Again your child can think about 'Part Part Whole' as they have 10 fingers altogether, 5 on one hand and 5 on the other ('Part/Part'). How many altogether? That's the 'Whole' bit.
Other little ideas: can your child play around with 20 straws or pieces of spaghetti. What patterns can they make? Can they practise counting 20 ( or 10 if they are not ready for 20) raisins? If they eat 1, how many are left? Can 20 (or 10) be split up into 2 equal sets? 4 equal sets? 10 equal sets?
Take some fish your child may have created last week. Paper clip a number up to 5 on each fish then help your child to 'catch' 2 fish at a time. Can you help them write out a little number sentence eg 2+3=5. Change the numbers to make up different sums. If your child enjoys this, have a look at subtraction, again starting off with numbers up to 5 and help your child to see that when we take away we have the biggest number at the beginning eg 3-2. Use raisins or berries to help them physically gobble up (subtract) the amount - how many left?
If you have a ruler or tape measure, ask your child to work out where 20cm is? Can they go around the house finding things that are 20cm long? What things are shorter than 20cm? What things are actually longer? Would they like to make a collection of their 20cm long discoveries?
And finally, have a look at a 20p piece. Draw their attention to the shape, size and colour of the coin. Tap the coin 20 times - that is how many pennies it is worth. Now look at 20 pennies- same/same! Then extend this to two 10p coins (10 taps=10 pennies value), four 5p coins (5 taps each coin) and ten 2p coins. Setting up a little shop with your child and helping them label prices on the things in the shop will help them explore money up to 20 through play.
Don't forget to show and tell us how you all got on using DB! Have a lovely number exploring week