Use benchmarks to estimate the sum,diffrence,or product
1 7/8+1/9
5 2/11-3 2/18
7 1/13×4 15/17
Please help I already have a bad grade in math
for example
7/8 * 9/9 = 63 / 72
1/9 * 8/8 = 8 / 72
add
71/72
1 7/8+1/9
5 2/11-3 2/18
7 1/13×4 15/17
7/8 * 9/9 = 63 / 72
1/9 * 8/8 = 8 / 72
add
71/72