First, memorize the “doubles” through 10.  For example:  1+1=2, 2+2=4, 3+3=6, 4+4=8, 5+5=10, 6+6=12, 7+7=14, 8+8=16, 9+9=18, 10=10+20.  Next, learn to figure around the number 10.  When adding 9+6, think 10+6 equals 16, so 9+6 must be one less which makes 15.  Also, 8+6=14, so 10+6=16, therefore, 8+6 is two less and is 14.  Write the math facts on a sheet of paper noting patterns around 10.  For example:  5+5=10, 6+4=10, 7+3=10, 8+2=10, 9+1=10.  Use a number line and 100 chart to calculate addition and subtraction questions so number sense will be mastered.  We purchased an abacus at a local thrift store which was wonderful to stimulate visual and kinesthetic learning.